There's a lot that can go wrong throughout a transaction and a good agent will do everything they can to not only negotiate for you, but limit your risk and keep you protected. 

@Lee Ripma is correct - as a California resident actively engaging and managing an LLC from California, California will declare nexus and require a registration, a tax filing and a minimum $800 fee each year.Marketing into other states may or may not create nexus (depending on each state's laws, so look them up) and need to register/file in that state, but as @Wayne Brooks indicated, you will most certainly need to be registered in any state where you want to sign contracts and otherwise conduct business in that state.From each state's point of view, anybody who wishes to sue you must be able to do so in the state where the transaction took place so you must be registered in that state with an agent who can accept legal service on your entity, should the need arise. 

It is extremely rare that a buyer or seller in a residential transaction will engage an attorney.. 

Better trust leads to better communication and a smoother transaction, leaving me more time to go get the next deal.

Find a good inspector that is trusted by professionals in your area and get a good pulse on the effective life of your big ticket items (Roof, HVAC, HW heater, etc.) and calculate out how much each will cost to replace, then do the math backwards for what you need to put aside for CAPex and maintenance. 

I don't think I should count the missed principal payments as cash flow because that is in effect reducing my equity in my property, but what about the interest I would not be paying for those two months?

The issue is that he will be effectively "removed" from CONUS and not able to put hands on anything while gone.

(No Snowball Effect)2.

This thread showcases the power of a good relationship with local lenders, and the SNOWBALL affect that follows if you use your Legos effectively. 

.- The one thing by Gary Keller (How to simplifiy and prioritise your time and efforts)- Pitch Anything by Oren Klaff (How to Pitch and sell effectively)- The power of habit by Charles Duhigg- Never Split the difference by Chris Voss (FBI based negotiation)Just a few alternate books that will also help you In your multifamily journey.