Some properties had lower vacancy because they severely cut their screening standards to put heads in beds, but their units were full of concession surfers who would take the one month free deal, never pay, wait to be evicted, then repeat at the next property. 

I am in the process of having my personal home appraised with the goal of increasing my HELOC.

The flexibility of those assets can increase greatly if you leave your job.

Should I increase the bid to their asking price?

No special development taxes...Sold One year now, 16% increase in equity.

Many towns have minimum housing standards.  

I would assume that with an increase in renter occupied units in an area, the competition would be higher and therefore it would make sense to go outside of the area of competition (given other demographic information indicates the area is still appropriate for a buy and hold strategy).

We've seen a huge increase in inspections, and they are very closely looking at roofs.

My rule of thumb for rehab costs is try to gain at least $2 value increase for every $1 spent on labor and materials.

Some towns have brutal rent control ordinances that can prevent you from increasing your annual rents.