I was also planning on paying cash for remodel but fix and flip supposedly includes this in their package? 

I understand how they are supposed to make money but when you take in $15/month and have to pay out $1,000 in claims, the economics seem off to me.

I suppose I'm more worried about when we outgrow the multi fam and decide to move.

The longer it was rented out can’t hurt either since it’s supposed to be an exchange of one investment property for another investment property  Your probably going to need a 1031 expert like @Dave Foster or a CPA to weigh in if you don’t have one. 

I suppose this might depend a bit upon what market(s) you’re looking at for the potential replacement properties but where I’m located investment properties are very scarce right now and when they do become available there’s many people making multiple offers on them which might make it harder for you to land your deals if the market you are looking in is hot.

So, I suppose you would shoot to stay under the 75% with purchase price, rehab, and any financing costs?

I suppose house hacking isn't an option for you at this time?

One of these opportunities I have been considering is investing in businesses like laundromats, as they supposedly can produce substantial cash flows (according to an investor I’ve spoken).

I have a business associate that supposedly has a connection into the world of MTN's and he's telling me that there is alot of money in investing in or brokering them for other investors.

obviously there are advantages for both products and I suppose it greatly depends on the type of investing you do.