I live in a suburban area with small lots. An alley runs through the back with a row of garages for all the houses. Think small two-car garages (mine is only 18x20). It's a safe neighborhood, but that doesn't rule out the possibility thieves from coming by. Most of the thefts in my neighborhood that I've seen documented are bikes getting stolen out of garages, or similar. But... most suburban city-dwelling people just put junk in their garage, not a bunch of expensive power tools.
I'm still growing my collection of tools but I keep a lot of stuff out there that would be awful if it was broken into and stolen.
So I always lock the knob and deadbolt of the service door, and on the overhead door I installed an automated deadbolt into the track from SureLock. Essentially it should prevent the OHD from getting pried open. I also removed the emergency pull and zip-tied the latch. The chances of needing the emergency pull vs. getting my things stolen is so low that I felt it was worth the extra security. My door opener has a self-closing timer so if accidentally unattended it will close in 5min and the failsafes will be back in place (no leaving the door open by mistake).
I do have a security cam at my house but it's not in or by the garage. Personally I prefer preventative measures as far as security goes. Having a visual record when thieves are successful, and the ability to "check in" on the place from inside the house or when away from home is definitely a nice feature to add on to the base security system, though. I may add a camera out there in the future, but another thing to consider is privacy of neighbors and family members when you're not on a huge lot. People don't always want to be recorded. So for me it's balancing that (not having 10 cameras pointed everywhere recording all the time) with being able to safely monitor things.
I've also considered door/window sensors and alarms, but I haven't figured out the best way to arm and disarm automatically as my garage is actually used as a garage as well as a shop and I doubt my family would be willing to set or disarm an alarm every time they went in and out.
In your situation, with a larger shop and property, I wouldn't think twice about taking extra security measures as long as they aren't a pain in the **** on a daily basis. That's where things like your keypad deadbolt come in handy vs. multiple keyed locks.
Plus, like you say, a lot of it is just piece of mind. And sometimes that alone is worth it. If a thief really wants to get in, they will. But a little bit of effort can make it a lot harder, and a lot less likely, and make you more comfortable.