Or will most HOAs allow special provisions for rehabbers to come in and flip without going through apparent loopholes? 

Garret Sutton's Loopholes of Real Estate is pretty good.

As a wholesaler when puting a house under contract , i had to put $500 of my own money , is there a loop hole that the earnest money can be put down out of somebody else's pocket ?

NV is getting expensive).Each property runs its own books, takes it's own PnL's and write-offs, etc... don't co-mingle funds to avoid anyone piercing your corporate veil and finding a loophole to attack all properties you have JIC something goes South on you. 

Nevertheless, I am glad that Bigger Pockets and the books I've read like Millionaire Real Estate Agent and Loopholes of Real Estate and Rich Dad, Poor Dad have given me the understanding to avoid deals like it in the future.I just finished my first BRRRR assessment using the calculator provided by another Bigger Pockets member.

If so are option contracts the loop hole around this to make a deal? 

As far as accounting books for real estate....there are books like " tax deductions for every landlaord, loopholes of real estate, etc" 

If there's a loophole now but the 'spirit' of the rule is to disallow it, then you can expect it to be shut down in the near future.

Maybe raising some revenue by streamlining the tax code and closing loopholes while keep rates as low as possible.

Im looking into pre-foreclosures for wholesaling and looking for at least 50% equity in the homes. are there any other loopholes I have to go threw to contract them since technically the bank owns the home. as for the pre-foreclosures that don't have enough equity to wholesale what should I look for to know if they meet the criteria to short sale?