For #1, you've got a pretty solid case and can just take them to small claims court. The window to pay is like 30 days and if the landlord waits longer, they've basically forfeited any amount of that money, even if it would be a legit expense (i.e. $200 for cleaning or something). 5 grand is definitely under the small claims threshold so you don't necessarily need to lawyer up.

I'm not really sure I can speak to the other issues. The elevator issue sounds more like bad luck tbh.