Deciding between a single-family vs multi-family investment is a common hurdle.

It is not common for conventional lenders to allow for escrow holdbacks. 

Is 3x rent income requirement (including voucher) common?

Trying to mix equity partners, tenants in common, etc to wonderful loans available only to natural individuals just complicates at your detriment.Add mom and dad to an investment property if you want to. 

Often, financial distress, sometimes triggered by medical issues, is a common cause.To find wholesalers, there are several approaches you can take.

I understand that IRR is the more common metric in MF.

Never heard of them, but this seems pretty common.   

This is pretty common.

You already are a broker, have something in common.

You are learning an all-too-common lesson: Tenants who stay in one place for many years are typically paying well below market rates, and they start to develop a sense of entitlement.