What other options would be good?  

Are there any options out there that won't tear away the margin on flips?

However, if managing tenants isn’t something your parents want to deal with, selling after renovations could also provide a large profit.Feel free to reach out if you'd like help with running numbers or considering financing options if you go the ADU route → I’d be happy to help!

With your focus in using house hacking, Conventional or FHA loans would be your best options.

I guess my only other option is to add padlocks onto the cash boxes on top of the regular keyed entry.

Offer custom lead mining would help me boost revenue because deal volume has fallen quite a bit.Johns scraper option looks really interesting though I’ve never heard of the site so can’t vouch for it.

That will start to tell you if rentals are a feasible option for you.

good area to buy. would love to discuss if you are looking for financing options

The reason why I ask is because that could determine what loan options are available to you (and interest rates). 

If you have equity and decent credit, a conventional Fannie Mae HomeStyle (or the Freddie Mac version) would likely be the better option instead of an FHA 203k loan (which will require a 3rd party HUD consultant to oversee the deal in addition to having the contractor involved).