So far I got only individuals with a rent limit of 1200-1600is it  common to let  2 - 3 individuals who don't know each other rent the house?

100% agree with @Collin Hays - find a local manager, preferably one not too large or not too small, I would say 30-90 properties is usually a sweet spot.

I prefer the multis because there’s one set of expenses and multiple rents coming in.

How much time / cash / other are each individual expected to contribute?

I generally prefer higher since I don’t plan on putting in small claims, it’s basically just for catastrophic loses and the savings in premiums over multpiple properties for multiple years should balance that out if I have ever have to use the insurance.

Quote from @Bruce Woodruff: Quote from @Jonathan Greene: Quote from @Bruce Woodruff: I think that this BP forum takes on that deal-killer function very well......at least it can if/when investors take the time to post their questions and concerns.It should, but because some (not all) investors are fragile about criticism or prefer an echo chamber, it often falls into a back-and-forth where we are trying to help on our own time, and they are rejecting it and calling us naysayers.

Some people prefer an electric dryer over gas and in some of our properties we have both gas and electric hook ups for dryers so they can have their choice.

Then split bottom line 50/50 with the partner (individual) after all other expenses are paid.

@Christopher Morrisi tend to think of 'cash flow' as a function of an entire portfolio rather than any individual property, or any specific month. 

So, some food for thought.Trusts seem to be the preferred method of liability and asset protection among the wealthy.