Don't wanna stick my head in the lion's mouth (odd how that saying works so well ) but whether there's buggy code in the scripts or not I can't say. What I can say is everything's fine here with all scripts disabled. Haven't encountered anything I'm unable to do but the login/out thing along the top is gone and I have to logout through control panel/settings. A minor inconvenience only though.
I'd think first though is Quant's having problems with scripts ON it's some setting(s) on his rig. I notice especially today with console games your avg gamer has no earthly idea how to tweak their computer's settings so accustomed to perfect 'plug n lay' on a console version. So I wonder if that kind of loss of technical know-how is cropping up with people thinking things should be smoothe sailing online but aren't.
My first thought would be if your OS can automatically download and install updates, that's where problems are gonna arise from. I know it's kinda counter-intuitive, but you should never let your computer do anything on its' own. Set everything to 'ask/prompt me' otherwise someone can easily hack their way in and mess with your box to their heart's content. If you think your browser settings are being hijacked on a specific site, it's probably because your browser settings are set wide open.
I've never used Chrome so I have no idea what you're gonna be looking at. But for Firefox, there's a setting under the Security tab to check that says "Warn me if sites try to install add-ons" so look for something like that on your rigs. Make sure it's checked so nothing's auto-installing things behind the scenes or worse. Security/Passwords has a couple box about saving passwords DON'T. Big target for hackers to download a passwords file. Look for the Cookies section and set it to 'ask me everytime.' Typically, the only websites you need to accept a cookie from is one you're typing things into. For simply reading, there's no need to let them store cookies. You need to let usmb set some though as we're doing both reading and writing. Everything else set to ask me or prompt me or whatever it says. Slows down rowsing a little bit, but it's worth it not having anything happen without your permission and awareness.
Lastly, if you suspect a site or script is doing something that messes you up, but a gazillion other people aren't hollering about it, it's just you.