If you house hack, even if only half of your mortgage is covered, you're likely still only going to be paying average rent in the area, right?

There's a couple things - you can get bridge funding now or some type of private money bridge/construction loan that will give you acquisition funds, so that you can acquire said building and then take the time to get your permitting squared, and then roll into construction portion once ready. 

(Max vacated rents - your monthly mortgage payment) = +/- net cashflow. 

In addition to my role in mortgage underwriting, I also own a duplex, which has significantly fueled my interest in the real estate sector.

Prop 1 SFH: mortgage amount around $950, rented at $2175Prop 2 SFH: mortgage amount around $900, rented at $1725Prop 3 Duplex: mortgage amount around $1000, rented at $1400($700/side)Prop 4 L/O Duplex: mortgage around $800, rented at $1850($925/side)What would you do here?

should i secure a mortgage?

Looking to bid in a few days on a Primary Mortgage lien,  it appears that there was an COA Lien which was filed with county on 11/22/22.   

If I bid and win on one of these auctions and there is no other foreclosure pending, do I get Title to the property and then negotiate with the lender to assume the existing mortgage?

It has a very nice private lot.

Very few folks at BP have had true training in Mortgage Origination, Probate, BKs, Divorce, Wraps, AITDs, CFDs, Lease Options, Title Problems, Sub2 and Land Trusts, negotiating with the seller, DOTs and Mortgages, subordination of notes, substitution of collateral, etc.