OCollector 2500 tavern silver.... impossible.
If your tavern is fully upgraded then that only two collections from the tavern over 24 hrs. You have max 140 friends. You only need 32 to visit. If it's short you can always visit them for the chance of getting spare change from sitting in their taverns. Aside from which if you visit them (and aid at the same time) they'll visit you more due to the event history in your town hall.
Gain control of 5 sectors..... impossible.
Work on your attack GBs. Don't do those sectors just yet. Once you're able to complete that province you won't receive any more DC quests for acquiring sectors until you scout another province.
I would first look up what the remaining quests are for the event before completing the province though. Depending on where you are in the questline you might need those sectors for the event
Edit: Looking at the time stamps seems you posted this in January. Hows your city going now? Has your city improved in its ability to complete DCs?
I mean on one hand the game designers state -- the game is meant to be played slow over a long period of time so do not suggest things meant to speed things up -- then on the other hand they give you challenges both in Dailies and Events that force you to move forward far quicker than anything remotely close to slow and steady. So its confusing which is it -- the game is to be played fast and furious -- or -- is it to be played slow and steady. It sure would be nice if they made up their minds.
It's a game that forces you to make decisions. There is no middle ground. Do or do not. Use the challenges presented to re-evaluate your cities current capabilities and decide how to improve it to match the challenges, or choose which challenges to abstain from.
You can go fast and get stuck. But luckily you can not lose progress. So it's easy enough to pick yourself up and get back on track at any time