Hi Happeh, welcome to the forums

Honest answer: don't know. Chances are if you try it it might well mess up. So assuming you didn't keep a back-up last time you upgraded (because if you did, you wouldn't need to ask the question) then make sure you do keep a back-up this time. Then if it does go wrong at least you can go back to 3.3.

I doubt it. Each version that has to do database changes looks for a secret code that tells it exactly where the database is up to. So 247 installer will see a number greater than the one it wants to get you to, and give up right there.

Without a database backup from pre-upgrade you're stuck. :(

Thanks for the replies.

you can disable the wysing editor, if you want

According to my host, the only file modified during the upgrade is "conf/_basic_config.php". Seems doubtful to me. I finally got my blog the way I want it with plug-ins, styles and a few minor hacks. Unless I'm overlooking something, I don't see any compelling reason to upgrade at the moment - especially if I have to re-work a bunch of stuff.