Making sure you are doing this in a house and community that will warrant it too. 4.

I'm not sure if the contractors are trained to exacerbate every single problem or not.We recently discovered asbestos in the compound joint.

But I would also make sure that you get a sewer lateral scope done to ensure the cast iron piping is in good shape. 

I make sure I screen each potential tenant thoroughly (background and credit checks) and require references.

Using a HELOC for the down payment on the second home might be an option, but lenders may require you to wait a few months post-closing on the multi-family before approving new loans.The BRRRR-style approach could work if you can renovate and refinance quickly, but make sure the timeline aligns with your lender’s requirements.

Not sure how many PMCs you've had bad experiences with, but we'll take exception to:"Then do a thorough research on tenant applicants (note: leaving this to a PM may be hazardous to your financial health)".BP seems to have more threads about screening mistakes by DIY landlords as opposed to PMCs.Now, if you'd have mentioned Maintenance, you'd get no argument from me:) Even the PMC industry acknowledges maintenance as one of the biggest challenges.Rereading my post, I kinda see how I sounded negative toward PMs.  

Not sure what collateral means2.What do you mean by "listed correctly" as in reporting the rental income on your taxes?

Surely they're collecting most rents, even during COVID.

Make sure you do your research as well. 

I would suggest making sure that you are following a set format/style of house each time you flip to systemize it more2.