Curious if there are software options for managing both types of rentals.

Does Baseline give you the option to track expenses without attaching it to a particular property?

There a handful that can do lower  than 620 at 50% LTV, however the rate will be very high My current score is around 670-680.

She’s currently not paying rent, and while she has some health issues and no stable income, she’s been communicative and open to general talks, with a possible option to vacate through a cash-for-keys arrangement, though this might take around six weeks and some hard work.I plan to rehab the property and eventually rent it out, potentially to a Section 8 tenant.

Contrary to most business lending, the REI industry has a lot of "non-bank" lenders that provide attractive loans that can lower your cost of capital and improve your profit/cash flow. 

I adjust pricing based on demand, like raising rates during peak season or local events, and lowering them in slower months to stay competitive.

Now, the older, house-hacked duplex comes on the market as a rental, lowering rental prices as another option available.Someone else moves out of their rent by the room unit, and upgrades to the duplex.

There's too many investors who are front page news in Northern states re CFDs gone bad and Texas where lease options went bad and the state enacted buyer protections...Take care to all.   

Looks like you have some good options in front of you @Martin Phinney.

I believe it to be a little Southern California hidden treasure for cashflow, mainly class C but if you know what you are doing its a really good option to invest locally in CA with decent returns.