Put everything in your favor just in case a tenant tries to pull an unforeseen stunt. 

4- If renovation cost / cap-ex turns out to be higher for some unforeseen reason, can the GP require investors to kick in additional capital?

Of course, major fluctuations in the macro-economy or significant unforeseen conditions could impact these projections. 

I have been looking at different properties and I wanted to get the opinions of some more experienced investors on here about the better route between investing in SFR or multi family i.e. duplex, triplex, quad.I am kind of tossing up the pros and cons between the two and I am still unsure which way I should go.With SFR I like the fact that they are more likely to appreciate in value over the long term but do not have as much cash flow while the multis have significantly more cash flow but will no doubt not appreciate in value as much as the SFR.I am planning to hold these properties for quite a long time 10+ but at the same time I want to have an exit strategy if I need the funds for another investment or something unforeseen in the mean time.Any advice/guidance/suggestions would be greatly appreciated.Thanks so much for your time.David

Writing into the contract that it's contingent upon a written agreement between you and the tenant on an acceptable move out after closing is fine, I would suggest finding a good local attorney to draft a stipulated judgement in that case and you may need to be ok with cutting them a check for a small cash for keys at move out.Other than that, cover yourself for any unforeseen circumstances.

Also with the multiple offer situation if everyone is bidding above asking price the seller may just up the price based on unforeseen demand.  

They never lose money, nor have carrying costs overruns, unforeseen zoning etc.  

After learning more about that particular sub-area, it isnt the right neighborhood, and including some unforeseen insurance costs, it isnt the property we are looking for. 

I just hate the thought of such a long term mortgage but no prepayment penalties mean we can pay it off whenever we want- so guess it makes sense to obligate ourselves to less should unforeseen circumstances arise (which they will- such is life).

He may have priced high to keep from getting the job or to cover unforeseen problems within the walls.