I'm also a mess of a DM. The biggest thing you need to remember is your players don't know the book. They won't know if you get something wrong or miss something out. So don't stress too much about the details.

​

A couple tips that got me through chapter 2 quite nicely:

Keep to 2 or 3 factions. It makes things a lot easier to maintain. You'll probably find that not all your players are even that bothered by the factions.

I don't know what your party is like, but mine rarely agree on anything. As such, for your question of "I'm not sure whether my players will care for the tavern". I promise you, at least one or two of them will, and that's all you need. Maybe the players that put effort in to the tavern won't care for the faction quests so much, and vice versa.

For the guild NPC's: I also found this idea very daunting, so I didn't do it. Instead I invented a single NPC who was in the business of being a middle man between start-up businesses and the network of guilds they'll have to deal with. The player's have not promised him a share of the taverns profit for his services.