The obvious starting point is with the basic assumptions of six encounters in a day. That's something which basically never occurs outside of a dungeon scenario.
It's actually quite doable to maintain that tempo in a city when "things are afoot".
8 AM: The PCs have breakfast. An informant shows up - she knows something but he's afraid to talk. PCs must convince her to give up information - an ally of the PCs has been robbed.
9 AM the PC see their ally - the alchemist - he is very glad to see them, he was just about to send his servant! An item he was working on - a vial of blood from one of the PCs - has been stolen. Consequences could be serious. Luckily, he had counter measure - the floor was covered with invisible ink, he has a potion that allows to see the invisible footprints, allowing PC to follow. He also suspect who the thief is, it's not the first time this has happened, and urges the PC to scare the crap out of the thief and retrieve the vial. He also is curious as to who wants the vial...
10 AM: The PC follow to a large in and stake out the place. The thief, Om Swar the Yellow, is a bit of a coward and particularly slippery (he's a mage!), so they have to do this right. His door is guarded by two thugs. They manage to foil's Om Swar's escape and learn he was hired to steal the vial by the Blood Merchant - he already has delivered it.
Noon: reconvene with the alchemist - this is very bad. The party agrees to steal the vial back.
2 PM: initial reconnaissance and info gathering.
4 PM: a social encounter at a magical auction house - already scheduled, PCs can't get out of it.
6 PM: random encounter in the streets -a funeral rite goes terribly wrong, undead spirit attacks.
11 PM: The PCs infiltrate the warehouse and steal the blood - but
gasp a slugman is held captive in the basement, being used as an involuntary blood donor. This has been going on for over a year. The Slugmen are the ruling class in the Yellow City, the implications are huge.
2 AM: The PCs get roped into a nighttime assault to arrest the Blood Merchant.
This is a brief recap of a real adventuring day - took 2-3 sessions too.