Just wondering how you update it , your in Ireland yes?
Updates allow you to use some new devices that come out and fix any issues , although mostly I only needed to update for devices , firmware seems stable otherwise
Basically you need to ask on an electricians forum because most on here don't install this panel the electrician will also probably be cheaper but you might not get much aftercare if that's the right word still maybe someone will charge you 400 quid if the cables are already installed
What area of the country are you?
Some nvrs have built in IP server , so will allocate IP for you
Some.equipment is all manually assigned
Dual port nvrs are good , but some more complicated than others
DNS is an issue lol
Subnets need to be common between NVR and cameras in most cases I think
You could install an internal bell sepratley as thatsore import than the external one in my opinion
Then if the panel has a set output you could use it to trigger some kind of timer relay set to like 2secs to trigger a buzzer , relay would trigger only for short burst , then using a Hi lo sounder with correct relay config to trigger sound when unset
Or some blag like that
But by the time you work this out you could have swapped the panel for £70quid
Stick to what you have , everything else will probably be more expensive if aiming for quality
If you want cheap and cheerful you can try any Onvif camera generally