Single-family homes are a great option that a lot of people feel more comfortable as opposed to MFHs.Multi-family homes generally have higher rental income, so if you are interested in a buy-and-hold strategy, then MFHs might be the way to go.

While I'm not exactly opposed to it, it's not my preferred method.

@Klodian H.Please note that while there is certainly asset protection for 401k plans at the federal level generally, please note that for individual Solo 401k plans (as opposed to a 401k plan that you might have through a day job) the federal protection outside of bankruptcy does not apply such that one must look to the state level where the creditor protection may not be as robust. 

Is it better to buy higher price point rent per unit apartments as opposed to buying more units with lower rents.

For example, I fund payment for roof replacement and therefore can deduct the depreciation from my taxes as opposed to splitting it 50% with partner.

I see a potential problem in suing in GA as opposed to going where the debtor is.

As I get more experience, I will not be opposed to "flipping" properties in order to quickly build cash for future investments. 

This is no longer up to the current plumbing code in our area, but the valves of course are grandfathered in.Plumbing code enforcement in Allegheny County is handled by county inspectors, as opposed to the municipal regular building code enforcement.

I am not opposed to residential, but since I'd be investing 1-2 hrs away from my primary residence, I'd probably have to use a property management company.

This is as opposed to leaving it sit empty while I keep trying to sell it.