Well, let's be clear. 'Rooting' is a simple 30 second process, since it's essentially just installing an app. Not much risk there at all, if any.
But custom ROMs are what most people root for, since they bring all the fun stuff. In my opinion it's 100% worth it to switch to a custom ROM, but that might not be true for you. Are you prepared to tweak and fiddle with your phone? You can a
lot more out of your phone, but you have to put more effort into setting it up. (And you may become like some of us here, flashing a new ROM every week
)
Flashing a custom ROM is actually pretty safe. You might get a phone that can't boot if something goes wrong (happened to me last night as it happens), but you can always pull it back again. Short of flashing files you shouldn't be, radio files are the only dangerous things you can flash. But so long as you know how to do it, radios can be flashed safely too. Lots of people here, my self included, have flashed radios plenty of times.
Of course, if your current radio works fine, it will work fine with a custom ROM