It is kind of strange to me that she does not use the rental property business account to pay for the property tax directly since she is authorized to use the money in my business account.

When you have that kind of uncomfortable power over someone, that kind of authority, you're really shirking your responsibilities to act as an authority figure by trying to be their friend.Should it be so uncomfortable and lonely?

They prefer ultimate authority and control because they're managing hundreds of units, they prefer to simplify their system to one process only. 

Watch the zoning on this one and make sure, before any construction is started that turning it into condos is allowable by the zoning authority.  

The IRA owns the LLC, but you can be the non-owner manager of the LLC and have signing authority.

@Jon Lopez, yes I would want someone in authority to sign for the LLC and the individual to sign as well.

Right now the plan is:Analyze deals for a few monthsBecome an authorized user on my parents credit cardsGet pre-approved for a loanClose on a deal, 5% down, before I apply for financial aid (primary residence isn’t considered)Any other advice/notes?

I literally teach this to other professionals.While not substantial authority the publications even give this guidance.here:https://www.irs.gov/businesses...And here:"Corporation to partnership.

Next, check the AHJ's (authority having jurisdiction) pending code changes related to STRs.

I suppose you could help, but it's not your property so you don't really have any authority and there's the risk of something going wrong when working closely with the sellers.Personally, I would keep the existing reservations unless they're 20% or more below market value.