The large power supply capacitors can be lethal,if they don't discharge properly after power off.If the tv/monitor is working properly though it should discharge itself properly straight after power-off,and i've opened a few monitors,tvs and amplifiers and have yet to find any charge...its not worth the risk though so I make sure to disharge every time,as you never know when it could happen.BTW these caps are probably more dangerous than the charge in the crt as the crt charge is very large voltage but low current and unless you short it straight to your heart,you'll probably just get a mighty scare....not recommended if you have a heart condition though,lol.
I guess other risks are crt implosion on older and some recent monitors i.e don't drop any tools on the tube or could get glass flying everywhere and lose an eye in the process.
Besides those few risks theres really not that much to be worried about ,people tend to be scared of these things simply because they don't understand them,but if you always take the proper precautions and have a decent understanding of how it all works inside you are very unlikely to hurt yourself and sometimes you have to get inside them if you don't want to pay through the roof for a new monitor or pay for the labour costs of a serviceman to do it for you and if your building a cabinet you'll probably have to open up at least once to wire the thing in.
DL