Other members have given you all the information you need; no successful covert attacks against the EVVA MCS are known to have occurred. The door and window hardware, and any other reasonable access points must be immune to covert entry. Have a professional alarm system installed.
As for the stalker 'easily' hacking your CCTV system... I have my doubts about that, but you can install a separate, stand-alone covert camera such as these ones: http://www.dhgate.com/wholesale/wall+socket+camera.html That will keep recording even when your system is 'hacked'.
I'm not even sure if it's possible, but if your stalker's locksmith friend is a Mul-T-Lock dealer and agrees to decode and cut unauthorized keys for a MT5+ as you said he is doing, then he is criminally complicit in this elaborate (and unlikely) plot. If you are serious you should contact the police, hire a reputable PI, armed guards, or something to that tune.
Owning a violent, bloodthirsty pit bull that you keep home when you're out would be a pretty good deterrent, but you can't raise one until your spook has done all the stalking he would like to.