Much like in the Baldur's Gate: Descent into Avernus Adventure, the party needs to look into the various activities of the Cult of Zariel which includes murder and that's what happened but the party would probably know what to expect if they did the previous module, DDAL 09-01: Escape from Eltugard. Also, for obvious reasons, these modules won't have exciting and labyrinthine dungeons for them to explore. This may be a good thing if you want to be light on the dungeons and props.
I still think having lots of minis and terrain is the best.
Stopped at the gates of Baldur's Gate (Did you see the cleverness of the title?) and seeing the gates closed (again if you've played the Baldur's Gate CRPG), the characters are directed to the head honcho of the specific gate that they're trying to get through. Basically, you are going to do some paperwork and negotiate with people. Not as exciting as combat but it does teach the player that goals can be achieved through non-combat i.e. talking.
Prepare your butts for some non-combat encounters.
Don't spend too much time on this part of the adventure as per the module's suggestion since it's just narrative busywork and somewhat resolves itself in the end. Registration of the Eltugardian refugees can be handled by any of the named NPCs and you can trust the refugees to look for work on their own as well as sell off the carts and animals they brought with them. The two main tasks that would require the party's skill and "being the characters" is getting a cleric from within Baldur's Gate to clear and certify the refugees to be free of disease, and acquiring housing for the refugees.
Do take advantage of the few combat encounters this module has available.
Please do note that Baldur's Gate is technically under lockdown during this period as per the Baldur's Gate: Descent into Avernus Campaign. So, no one is allowed in without explicit permission. However, the Flaming Fist at the Basilisk Gate will allow only the characters in for an appointment with Flame Daryn Falburn. Flame Falburn will provide permission to freely to enter Baldur's Gate once they've met for the first time. So any unauthorized entrance, e.g. climbing over the wall, into Baldur's Gate will be met with Flaming Fist Lawful Aggression. One of my players did this and got spotted thus Flaming Fists is now on the lookout for him.
"I AM THE LAW!" - Flaming Fist Guard.
If you're not too sure about what temples are available, choosing any of the "socially acceptable" gods and goddesses such as Helm and Lathander should be fine. The Baldur's Gate: Descent into Avernus Campaign and Sword Coast Adventurer's Guide don't seem to specify any of the temples that are actually in Baldur's Gate. However, if you want to know what are temples are available as per the Baldur's Gate CRPG (It may not be canon so take it as a suggestion), see the below:
1) Temple of Helm (Northwest part of Baldur's Gate in the Upper City)
2) Shrine of Ilmater (Northeast part of Baldur's Gate in the Lower City)
3) Temple of Tymora (West part of Baldur's Gate in the Upper City)
4) Temple of Gond (West part of Baldur's Gate in the Upper City)
5) Temple of Umberlee (South part of Baldur's Gate in the Lower City)
Suggested locations of temples in Baldur's Gate. Note that Temple of Umberlee should be somewhere on the docks. Map is from the Baldur's Gate: Descent into Avernus Hardcover Adventure Book. Notice that most of the temples are located in the Upper City portion of Baldur's Gate.
Again, don't be too hard on the players when acquiring the cleric. I suggest a donation from the party of whatever amount they are able to donate. They don't have to give everything but they shouldn't be stingy. When I did my play through, the characters (or rather one of the characters that can heal or have medicine) opted to switched places with the priest of Ilmater. The reasoning for this was they were willing to do it for free but since they would do it for free, most would flock to them instead of the temples in the Upper City thus they're overcrowded and don't have a free hand. The priesthood of Ilmater in Baldur's Gate however, actually reside in Baldur's Gate thus they are able to check and clear the refugees of disease whereas the characters don't line in Baldur's Gate (Supposedly).
The module mentioned at the end that a warehouse is made available for the refugees as temporary housing. However, the players may not know this and go on to find said housing. If they ignore or delay finding housing for some reason, it's fine but if they make an effort and for the sake of continuity, make it very obvious that there is an old wool warehouse on Stormshore Street, near the docks that a merchant is not using. The merchant is willing to rent it out to the refugees on a temporary basis until the refugees can find proper housing.
Around this point; if the party managed to capture Vollis Foote and hand her over to the Flaming Fist, Bonus Objective A would be available and happens in the Outer City. Highly recommended for variety and if your players want to have some combat.
The next day when the characters got everything in order, either they would come of their own volition or summoned by Flame Falburn. It's another detective scenario! Just so we get to the point, the murderer is Harwin, a tailor who also owns a shop, Harwin’s Garments & Knits. In my opinion, the trail of clues is thin and circumstantial, and "meta-ing" since of all the things you've mentioned, one of it is a dress made by Harwin and worn by the victim's (Markus Hallgate) wife, Bolnata. Additionally, Harwin's shop is "close by" to Markus’s leather goods workshop. Again, in my opinion, circumstantial. In addition, the murder weapon apparently was "slender, pointed instrument" which can be mistaken for a rapier. Harwin murdered Markus using a brass needle i.e. one of those longer and thicker needles for knitting. Furthermore, the other supposed "lead", Dovis Tobergate, does not give useful information for Markus's murder and could throw off the party in their investigation. The other murders mentioned by Dovis are done by others but still under the influence of Gharizol.
Below are what I recommend to improve the scenario and provide more clues so that the characters would be more likely to investigate Harwin:
1) Point out that the wound is too thin to be a rapier when examining Markus's body.
2) Add in a scarf that Bolnata has that was knitted by Harwin as a gift.
3) Bolnata should mentioned that Markus has issues/grudges/fights with Harwin regularly.
4) Bolnata should also mentioned that Harwin was very nice towards her to the point of creepiness.
With the mentioned additional clues, the party should be able to focus on Harwin and the rest of the investigation can go on smoothly. The rest of the scenario plays out quite alright i.e. catching up to Harwin and some combat with mercenaries and hired guards.
Last scenario of the module, i.e. Bonus Objective B, which again I recommend doing if you have the time, is about the party defending themselves in a court of law. It should be mentioned that you can only do this if the character have met with Dovis Tobergate otherwise the case against the party has no grounds as opposed to shaky ground. Another fun and interesting scenario and seemed better thought out than the main quest of the module. Feel free to use any law court tropes for this. As long as the characters make reasonable arguments or roll 20s, they should be judged not guilty.
Another criticism I have for this module and later modules is the logical misstep, poor editing and continuity issues. The first of which is that you should be approaching from the east and entering through Basilisk Gate. Second, Dara is indeed 10 years old so may be a bit too young to be a young woman. Third and lastly, Zook mentioned something happening "a couple of days ago". The sequence is confusing so I recommend having Zook only mentions Harwin is leaving Baldur's Gate to check on shearing operations and he should be exiting through the Black Gate. Do not mention the "couple of days ago at the shearing operation" bit.
The idea for this module has a lot of merit and nice balance of combat and non-combat encounters. However, the murder mystery element is a bit too thin on the clues initially especially trying to get players to investigate Harwin aggressively. Also, first part of the module, i.e. the process to get Baldur's Gate to accept the refugees, doesn't seem to contribute to anything especially in the end, the module just resolves the issue so it's just a distraction and needless paperwork. Again, as said before, there's some editing and continuity issues in the module that should really be not there after some proofreading. TL;DR: Too much pointless tasks, too few clues, and not enough proofreading and editing.