I plan to install new locking mailboxes, that would also allow for secure package delivery.

I wish you luck in your hunt, and it will surely help to have a reliable local acquaintance act as your eyes and ears on the ground.Feel free to reach out directly if you have any other questions/just want to discuss!

First and foremost, as you're changing out the locks on the doors, install doorbell cameras on the exterior to cover entrances in/out of the property.  

Does it render the lock unusable?

I would be curious as to what the average billing is to a buyer or seller for a completed transaction.Also in IL were the attorneys have a lock down on the closing process agents do NOT do as much work as in other states not by a long shot..

That locks up the equity.  

If i decide yes, how can i lock myself down in addition to security systems, cameras, legal self defense, and anti-theft door/window stoppers?

Have assignment contract ready to sign but need to lock up funding first.

So, the family member is pocketing cash and guaranteeing a stable cost of living for themselves basically locking in their future at a time when values are high.

Are you more inclined to speculate that rates will fall lower (they should, I think they are likely to, but they may not) and you can refi, or would you rather pay a fee/premium to lock in where you're at now and hedge your risk of not being able to refi into a lower rate?