Yep I agree.
Looking at budget, and the fact you stated low maintenance.
I'd make sure any door and window locks are sufficient, add or upgrade if necessary.
Dummy box and a few battery powered adhesive shock sensors on vulnerable windows.
Maybe you'll have change left for a pie dinner.
Well done, bear in mind most engineers would have been expected to complete that job in 8 hours too
Nice to get some respect for a change.
I wouldn't expect them to rush the firmware out, I wouldn't worry about updating either unless V4 had extra feature you need.
If there's your panel version in the flasher software your good to go.
You'll need 3.02 firmware, make sure lead is plugged on the flashing port correctly and it's detecting your COM lead. Flick switches and buttons as required via instructions.
I would use Client-Server distribution and secure the system using higher end equipment (DVR Router Firewall etc) with these I could utilise VPN's and VLAN's.
If it was not a requirement for remote connectivity I would disable it.
There is no step by step instructions available. It goes far deeper than "DNS" and "P2P".
Every network and site is different and most DIY kit is easily compromised.
Security is about layers, the bigger the carrot the more layers you need.
Yes it is possible your device has been compromised and that it has been used to pivot attack other devices within your network.
With a pivot attack the routers firewall is rendered useless.
You should at least change all of your passwords for online accounts and disconnect the DVR from the network for the time being.
DMZ is a way of placing a device outside of the firewall, this may have lead to the device being found to be compromised in the first place.