I am thinking about giving the IMAP Gmail a try on my BlackBerry, so I was gonna remove current POP account(s) and re-add as IMAP and I am just curious, will I lose all my previously saved email? (Are saved emails linked with the email account or are they stored seperatly on the BlackBerry?)

P.s. I would try searching for the answer (as I am sure I can not be the first to ask this) but I can't seem to get the search going on Opera Mini (4).

No, they are not linked and won't be removed from the BB just because you delete the email address.

For safety sake, just do a complete backup first with Desktop Manager.

Good luck.