I will have 80k to use therefore i am wondering if I can first live in the house with an fha loan, fix it up (painting, some remodeling), move back out and invest in a second after i am allowed to rent it(fha waiting period)? 

You must have a good grasp of the styles and architecture of historical periods. 

Do you think they could claim that since my notice was defective that I shouldn’t have been able to deduct rent for the remainder of the 30 day period?

Most municipalities require an inspection prior to hooking the power back up if it's been out of service for an extended period. (6 months in my experience)If you recently acquired this property or are just now getting to rehab it, it may be worth the fee to have an inspection done on it (the type you'ld have prior to purchase).

@Rey Ruiz There is a seasoning period for a loan, but they typically sit around 6 months or so.

Can you still negotiate during a due diligence period even if your sales agreement was "as is"?

FHA for primary residence at 3.5% down, with a time period before renting it out.2. 

I thought if I was able to collect all of the rent for some period of time to recoup the rehab costs before I start paying the owner.

You want a HELOC or RELOC that allows as much ARV as possible, has low interest, and has a 10 year interest period first before principal is due. 

In option period for a tenant occupied four-plex.