Right, so that's a bit over specced for a space that sized.
Here's a smoking deal. C4 remote + controller for $360. Can control your HW system, no problem. The only issue would be the rack - how far from the controller and any required physical connections. But there are C4 drivers for Global Cache stuff too.
The EA1 is a bit underpowered to run a whole house system. If you're running video/audio they used to recommend it for a single room as part of a larger installation. EA3 is probably the minimum for whole house, especially on the latest software.
We have C4 still running OS2. I keep putting off upgrading to the EA line.
EA-1 is not likely underpowered unless you are wanting to control a bunch of AV stuff. I've seen EA-3s for about $300 on eBay. OS3 is a big upgrade and probably worth it.
I'd ask the previous owner for the password. The website is https://customer.control4.com. Otherwise you'll need a dealer to transfer the equipment to a new account. You'll need a dealer anyway to do the OS upgrade. If you want to stay away from local dealers you can find remote programmers on https://www.c4forums.com/
I will partner up with a dealer for sure. I am still leaning towards moving all Electrical over and leaving the Control 4 for Audio. I can probably sell the Control 4 devices for close to the cost of the Lutron devices. The customer wants simple no matter what.
My neighbor that just moved in had the same situation. He ended up going with the Savant system for cameras and music. I helped with Hubitat for lighting and automation of everything else. He seems to enjoy it because he doesn't know any different. The Savant equipment is locked down tight and I don't want anything to do with it. Sounds like you are getting it figured out.