Worst case is hard to predict of course but I guess you end up losing the place or paying them a lot of money as in cash for keys.How would you handle maintenance?

Also, I could point to the active/directly owned investments that have failed in this mini-downturn and claim that "all" directly owned investments are too risky (and that direct investors are too dumb to handle real-estate etc).  

Hire an attorney, take notes, and maybe you'll be prepared to handle it next time.

Experience with Multi-State Taxation -  Do they have experience handling income from out-of-state properties and navigating California’s specific tax requirements for LLC members?

If looking to scale flips and create systems around it to minimize your time and involvement, I'd highly recommend putting a team in place that can handle the day to day operations. 

If a tenant wants to break a lease, there should always be something stating how this is handled in your lease agreement.

If not, how do you keep a handle on everything, especially everything related to renos/construction?

My basic philosophy is that if you can't handle the little things, then you can't handle the big things.

When working with out-of-state agents remotely, try asking about their experience with out-of-state clients, their take on market trends, how they handle issues if you’re not local, their communication style, and if they can share any recent deals or references—it’s a quick way to see if they’re a good fit without being there in person.

This is how I handled.