Wood burns and sheetrock is fire-resistant.

Also check if the wiring is aluminum, I'm not saying don't buy an aluminum wired house but I don't like the idea of my rental properties burning down and if you can avoid it I would unless the deal is sweet enough.

Berwyn and Forest Park both do this a lot and what it means is your unit is legal unless the place burns down more than 50% or goes vacant for a year. 

We're looking into house hacking as a way to start, but we fear it might be too slow of a burn starting at age 29 that might not pay off in the end, especially since we don't want to live in a duplex forever...we have to get out of it somewhere, somehow.At $3600/year, it sounds totally unfeasible to do anything beyond our brokerage $500/month investment as any sort of savings for anything, whether benefitting the house or possible future expenditures and this has been bothering my mind for awhile now and created a lot of stress involved with the house. 

It is so hard to break into this arena and you could get burned until you have some experience. 

I don't want to be rude or burn a bridge, but I also don't want to sign a bunch of these with each wholesaler JUST to get property details. 

I don't want to shoot myself in the foot by burning a bridge with the seller if my expectations are off-base, but I don't want to be made a fool of either. 

I'm figuring $15k of rehab on burn units. 

Tenants with money to burn can afford to move and lose the security deposit whenever.

@Greg Gangle it’s safer in my opinion to take your cash and stack it so you have an extra fat reserve account, ie if you pay extra on the mortgage you have to refi, sell or put a Heloc on it to access that equity in the form of real money.