1. are you on contract or pay & go? Have you tried sending a text message with the word internet to 3064 (i think thats the no.) or best of all calling 150 for help?

2. Camera issue i dont know much about, might be a problem relating to issue 3 that mucks things up a bit

3. Had a similar problem whilst transfering videos from my PS3 to n900... mustt be because of the new file system the PS3 creates on the N900 which totally bars you from doing any changes on your own phone...you dont have authority or smthing like that..(you shouldnt even be able to delete any of your files!! How lame is that!! my own phone too! lol)

my solution: You need to delete the extra files/ folders the PS3 creates...sry cant remember what they were right now, but you should know the strange ones showing up in your file manager.

Now note : windows 7, and linux ubuntu couldnt do it...but i did it successfully on mac osx...(one of the pluses to having a triple booth rig on your pc) on the mass storage mode option... cant pro-offer any more info, cuz i stopped looking for when that worked.
Once thats done, everything worked fine..(i did do a rebooth of the phone, but not sure if you absolutely need to)

so get your self and phone infront of a mac & delete those new files..
who knows your camera might start working again.

Good luck!