This description window should be wide enough to hold patches without mangling them due to word wrapping. Alternatively, arrange for this window not to word wrap.
AFAIK patches are supposed to be sent over e-mail. See http://developer.redhat.com/bugzilla/redhat-faq.phtml#howdoipatch for more information
Yes, the preferred method is to open a bug, and then mail a patch into bugzilla as documented in the faq.