It's an expensive bridge to value add, flip RE, or close on a deal all CASH.

You will need to read your ICA, Independent Contractor Agreement to see what happens to your pending sales and referrals if you leave before they close. 

My question is.....do I have to buy/close on the property before the June 11th auction? 

I would suggest that you jump into some local meetups, get connected with local investors and real estate agents who can help you on your path to running numbers and getting your feet wet on actually knowing more of a good hard cost for rehabs. 

Most of the lenders I’ve had contact with have the 25% DP requirement, high rates, and high closing costs 

@Eric LoweI am also an investor friendly agent in Denver.

Look for houses on sites like Zillow, Redfin, and Realtor.com, and get help from a real estate agent.

If a PMC only charges an owner a flat rate leasing fee of $500, what amount of commission can they offer on the MLS to an agent that brings them a tenant? 

A heloc is an open end mortgage or in simple terms its a high risk credit line similar to a credit card that sits in 2nd lien position adding another trade line to your credit and reducing DTI.Just like a credit card if you ever miss a payment on any debts on credit or if your scores drop unexpectedly they bank can close or reduce your line of credit.

I got a 3% mortgage, and closing costs covered.