I have about 50k I’m willing to be aggressive with.

There may be site specific or submarket specific factors that justify paying this price and cap rate is not the end-all, be-all justification to price an asset, but in general a cap rate in the 4s for a c class multifamily property is ultra aggressive.

As far as the aggression, make sure you report every incident and instruct your tenant to report to animal control as well so if they ever do harm anyone, you've got a recorded history of violations.   

Will renters then move away from the city (due to no longer needing to commute) causing a bigger supply of rentals in areas near cities?

There is not much supply though.

This tends to be a blend of skills in contracts, negotiations, managing a GC to perform, supply chain management, etc...

I'm partial to multi's, as they are limited in supply.

Limited supply.

if i'm the owner of the property (my partner doesnt have his name on the deed or the mortgage) and we use his vehicle for going to and from the home supply store to pick up material and run errands, is his mileage deductible in some way?

Follow up for the curious: I found an aggressive private investor to fund the closing cost on the deal ($10,000) With cash in hand, I was able to negotiate $10k off the asking price and close in 5 days.