.- Depends on what you're doing specifically, but usually I'd recommend getting an EIN at least to give access to business bank accounts- Repeating #1, if you're going to a property and 100% of your time is spent doing renovations and the like, sure, but if any of it is for personal benefit, that'd be disallowed.

Second to cash in the bank is HELOC cash because you can use it however you want (you just have to see it already in an account).

Quote from @Gregory Banks: I would hire a structural engineer. $1,000 inspection could save you tens of thousands.

I've done it multiple times on primary residence and was just able to do it on an investment with a local CT bank. 

Regarding a HELOC, most banks will only provide a HELOC up to 75-80% of the property value, so you may not be able to access a HELOC for a while.

For me, I am a little hesitant because I would be in a situation where I would be trying to secure traditional lending (which should be very feasible given credit scores & what $$ amount I am pre-approved up to from my banks), meaning that I assume I would be forced into using my first-time homebuyer loan incentives.

If you can get a better deal on the home due to age its a fine and if you need financing banks do not judge year built. 

Credit unions, banks, mortgage companies and private lenders.They all had the same answer.

I had a local bank provide a 1031 without fees. 

A local bank relationship How did you add value to the deal?