Is the 70% rule relevant as a quick screen tool for BRRRR investing or is that only to be used in fix and flips? 

Get a few contractor estimates to get it up to market comps and compare what you could sell it for fixed up vs as is.

How do I go about fixing this issue?

I'm looking for a HELOC and been going to different banks to find the best rate in New Mexico but they all seem around 7% for a 10yr and most is not fixed does anyone has a recommendation or suggestions it would be awesome. 

After our house is fixed up, I think it should be worth about 725K based on the comps, with no market changes.

It was a $300 fix.

HML fix & rent of $165,000 @ 15% over a year - Monthly payments are $2,062.50.

So the concept is live in it temporarily, then move out at first chance once I can get that unit fixed up and rented too.

Plus their minimum balance to not get fee-d is little high.Also US bank has now twice locked me out of my online for no reason whatsoever and one time they said the only way to fix it was to go to a branch.

If they catch you, they will drop you like a hot potato.You can rent to someone for a fixed term of 6+ months and then renew or extend on a month-to-month basis.