With my new HELOC, I am not sure if there are other options I can do to earn a higher gross yield, say 8% or above on  the purchase price.

(Tech works earning 6 figures+ or is it more of blue collar type)What does living in San Tan or comparable areas feel like (Eg: Does it have good hospitals, parks, schools, well maintained roads etc?

I may even Uber it up for some extra income.

Goldman is just about half way in paying back the fines so they will most likely be still doing their massive buy/hold/forgive debt to earn the credits needed to forgive most of the remaining fine balance.

Building 3 is a conventional loan, I earned the 25% down for it with bitcoin :-D So I'm all about doing what I can to make this happen. 

Many first time buyers out there do not have the extra cash to remodel which is why they prefer a turnkey project. 

you earn your money for sure.

Is 20% down a good plan or should I do less and use the extra money for updates to the house?

The units come pre-loaded with freon so dont let anyone charge you extra for that.

Oftentimes the seller will base the price on current rents and depending how far below market they are you can get a unit that is renting for $1100 that should be renting for $2000 to live in by paying the extra $15,000-$20,000 in relocation assistance, which if you treat it like an increase in purchase price is a pretty good deal.