HELOCs are not available because they are residential loans guaranteed by individuals and what you seek is a type of commercial loan or credit line which are available to seasoned companies with proven financial track record.

You could, for the purposes of verifying that you are not renting to someone who is potentially dangerous or financially incapable of shouldering the burden of being a roommate, ask them to apply through Zillow so that you can see their background check, that also gives you the opportunity to have others who might be interested in being your roommate as well, apply.

have you guys put together any SEC-required financial results for these? 

Let's assume that the neighborhood is a C class and the median income of the city is greater than 3X of the market rent.Here are some of the considerations I've come up with so far:- Units are in need of renovation and capex is too high or not available- Unit quality is not the same as market - Seller is worried about losing tenants due to increase- Vacancy rates are high or filling units have been difficult- Rent increase would take multiple increases over multiple lease periods to get to market rate if seller is trying to retain the same tenant- Seller inherited property and just want to liquidate- Seller needs to liquidate quickly (financial burden, sickness, quick exit from land-lording)It seems like I might be missing a warning sign about a deal if they are selling with current rents that are under market; but again, this seems to be most of the properties I've underwritten.And in the same vein, what should I be worried about when purchasing a deal with under market rent with the intention of raising them after purchase. 

Consulting a tax professional or financial advisor familiar with these rules would be a wise step before making any decisions.

Local lenders and credit unions could face insurmountable losses to their balance sheets and customer bases as well as the downstream financial and real estate service sector.

Depending on your market it may not make financial sense at all.

This gave us peace of mind and ensured that any unexpected incidents wouldn't result in major financial setbacks.These two choices have played a crucial role in optimizing our STR strategy, balancing profitability and protection.

Prioritize your financial stability.

Consider starting with a few lower-cost flips with a smaller loan-to-value ratio to reduce financial strain.Market Research: Sacramento can be volatile, so I’d recommend keeping a pulse on local trends—particularly in the neighborhoods that have potential for growth but haven’t quite hit their peak yet.