bbSpell will not have interfered with your browsers. Sounds like you may have accidentally hidden their icons? Hold in the ALT key and click the wheel on any icon, Select Show All. Are your browsers back?
To remove any application, you go to your BB Options, then Applications, scroll to the app you wish to remove, click the wheel, and select delete. Some apps will require a reboot to complete the uninstall (like bbSpell)
As for bbSpell, it would be helpful if you could specifically describe your problem. What do you mean by it not taking the registration code? Does the bbSpell Connectivity Test work? If not what error are you getting? The most common user problem with network enabled applications like bbSpell is that the blackberry is not yet properly configured to access the internet via the TCP control panel. Please see: http://www.somedevelopers.com/Support.htm#Support
Sounds like you purchased the product? If so, we provide phone and email support..