I don't think renaming other addons will help, it'll only make things worse.
Search? I find that word is usually a bit better at this, and don't search just UN_Forces, try UN then Forces and UN_ and stuff like that.
write-protection.
What is that? You just unclick the read only attribute. Unless you are talking to someone else and I misunderstand you.
In the end, if the forums here or the official ones don't help, just save the "good" addons in some folder and place it in a different place than the OFP folder (along with good missions you' ve made or downloaded) and reinstall OFP.