My concern is that if i apply for a HELOC to use for the down payment before i apply for a mortgage, A) I wont get approved due to my DTI ratio, and B) I wont get approved without first showing the bank I have the 20% down payment before pulling the HELOC.

If you don't learn to manage your investment well, you will eventually destroy your property, lose money, waste your time, or drive yourself insane.

Some people will, some wont.

When my contractor went without me they kept him waiting over 2 hours then told him something completely inaccurate and they take no accountability for how they can literally destroy peoples lives and finances.

The tenant base is generally 95% single women with 2 to 5 kids and they flat destroy houses, Not on purpose  most of the time but if you have children all below 10 years old they are just brutual on houses even in the best of situations of which single parent with multiple baby daddys is not the best of circumstances.. full stop.

The lender wont talk to you without the owners written authorization, and the lender does not own the property to sell it to you. 

Add in the current BLM protests where property is destroyed, the police do nothing, and some municipal governments even condone the behaviour!

Stay away from the top 2 banks, they can take months to actually finance you and saavy agents wont accept a preapproval from them because they can take forever. 

@Shak F. you wont be able to do a cash-out refinance with a conventional loan, since they require 12 months.

There is plenty of good turnkey properties on the MLS for sale that would cashflow using the 1% rule and you wont have to overpay for them on a "promise".