-How do you conduct background checks, and which services do you recommend?

Quote from @Nadine Wallace: You can do simplisafe with/without Wi-Fi, but you will need cellular service.

I recently started my own practice as a bookkeeper and tax preparer, and am excited to learn more about how I can help best service real estate investors!.

Other KPIs and considerations you should evaluate when talking to any lender who offered private placement of loans/notes are historic default rate, how quickly they can place your funds (do you get preference over their income funds, for example), average interest rate - borrower note rate and what is passed through to you, are loans serviced by a 3rd party servicer or in house.

That $3,000 is typically the annual cost for a full service property management option. 

then, there are holding costs while you rehab - servicing the loan, insurance, utilities, the rehab. 

We don't allow any "deal-making" in the forums, which includes advertising your services or properties, looking for partners, etc.

I'd check local STR FB groups and see if you have a local Real Estate Club.You can offer your services there, maybe for free in exchange for the experience.

I haven't used Furnished Finder's waiver but I've used similar services in the past.

I am not aware of any issues with using third-party screening services.