Depending on your investment strategy / goals, there may be other options rather than creating multiple LLC's.

That cost is highly dependent on whether you're pulling permits and doing plans with full engineering, or just common sense building without permits, of course.

Depends on what youre looking for.

Along with that, make sure the seller is either crediting you or giving the renters' deposits to you or back to tenants, depending on how you set it up.

Real Estate Investing is not hard.It is only hard when you do it wrong.Wholesaling becomes seriously easy the second you understand this one sentence.Your success depends on your ability to find motivated seller leads!

So the answer really depends on the areas you are considering.

This benefits the buyer more, since depending on how it is written, it can lock in a future price and if the buyer would benefit from exercising the option he may, if the numbers run against him he can back out. 

going to depend on the season and if your utilities are electric or gas . also will depend on the energy efficiency of the home 

Dependent on the countries style of ownership or lack there of.2. 

I may have even had them on board from the start depending on how difficult the process appeared to be initially.