While not every mentor is a guaranteed path to success, proper vetting through referrals, review of a mentor’s track record, and alignment between the mentee and the mentor can shine some light on whether or not this relationship is a good fit.

but working with someone who is local to your market, who can show you their legal documents that they have used, introduce you to a proper title/attorney office for drafting documents...I mean, nothing is foolproof...but that route will have a significantly higher success rate. 

Sounds like its time to sell since the HOA fee just doubled which usually means the HOA has not been managed properly and failed to build a strong reserve account.

How do you balance these considerations when choosing a location? 

If the taxes are killing your cash flow, you'll need to either negotiate a lower purchase price to offset the tax burden or budget for some property improvements that could increase rental income and help balance things out.

Cash flow, equity growth, or a balance of both?

Sure you could do a money market or put it in an ETF or something, but this is one of the options where the balance "can't" go down or is extremely low risk while making a decent yield.

if yes then you got the answer, an appraiser will never come in with the proper value of A turnkey, because they rely on local comps even though those comps need much work and the principal is already done and cash flowing.2- These turnkey sellers usually purchase there properties for far below market value, if this is the case the appraiser might appraise for A lower amount due to the previous sale on the property.I don't know what turnkey seller specifically you are talking about of, but if their customers are happy then you got your answer, if their customers claim they were ripped of then you got the answer as well.

You then draw your HELOC balance as the down payment for the flip.  

There are various other items that may come up such as: Proper firewall suppression, adequate entrances/exits for fire safety, stair safety, size of kitchen appliances, etc... for my specific example.