You should have a good idea of every expense you have in your primary home, then add the STR specific:  (These are rough estimate numbers, depending on various factors)STR insurance - a special insurance that covers both the property and your liability, could be $2~4k in areas without natural disasters, could be more than $10k in some other areas.cleaning fee - approx. $50 per bedroom, so a 4-bedroom house will cost you about $150~200consumables - bathroom supplies, kitchen supplies, beverage supplies: $20~30 per week, depending on how much you providewear and tear - towels, linen, kitchen utensils, some furniture: $1000~2000 per yearRepairs/replacement for things that guests break or steal:  $1000~2000 per yearAlso, if your personal use is less than 14 days a year, the entire property's expense is deductible against STR income, but if you use more than 14 days, then you will have to calculate the proportion of how many days it's rented out vs how many days you or your family uses. 

Glad we don't have a huge tax liability. 

You're spot on with the tax liability. 

Quote from @John Friendas Quote from @Patrick Roberts: If you are on the note or personally guarantee the debt, then it will affect the liability side of DTI, regardless of whether the lender reports the loan on your personal credit.

@Chungying ChuIf you want more liability coverage, ask your insurance company if you can increase it.

However, the replacement property must remain an investment property—converting it into a primary residence too soon could trigger capital gains tax liability.

None of the walls I'm shifting around are structural so no issue there but from a leasable / liability stand point what are your thoughts?

Equity is the value of an asset (in this case, your business) after subtracting any liabilities.

How does their "generous liability insurance and requiring renters insurance" specifically benefit owners?

You protect your assets by buying a landlord insurance policy, which comes with dwelling plus liability coverage.