Sync Iphone with a Linux OS?

No. That's what "back ups" are when you sync and back up your phone through iTunes.

However they might now. I'm a linux user, therefore I don't get the joys of using iTunes so I'm not up on iOS 5 and the new changes.

But your back ups are your stored info usually. Just not contacts. That's a sim card feature

If your on Windows or Mac. You have to use iTunes. It's a totally free download.

If your on linux. Use gtkPod. It's the simplest iPhone, iPod media manager they make for Linux since Apple don't make an iTunes for linux

First of all, can not guarantee that your iPhone will work with that Handsfree Bluetooth, regardless of what any of it says. The iPhone is manufactured by Apple to work on its own, it is not made to work with any of these 3rd Party products, contact that manufacture for more information.

First thing I would try is on the iPhone go into your Settings > General > Reset > Reset All Settings (NO YOU WILL NOT LOSE ANY DATA) Once you tap that, it will inform you that it will NOT erase any of your data, simply just resetting the settings, getting rid of any glitches. Test it out after this, if its still an issue, continue to the next step.

Best thing to do, since this mostly sounds like a software issue. Restore the iPhone using iTunes and a computer (Download iTunes here: www.apple.com/itunes ).
-Plug your iPhone into your computer using your USB Cable that you plug into the charger with.
-If possible, plug into the back of your computer if you're using a desktop.
-Open iTunes on your computer, make sure its fully update, a message will pop up telling you it needs to be updated. -When iTunes is open on your computer, you should see your iPhone listed in the left-hand column beneath Devices -Click on your iPhone, in the main window of iTunes you should see a Restore button half-way down the page, click that and it will ask you if you're sure.
-Agree to the terms, yes this step is going to erase all your data on your iPhone.
-iTunes does automatically create backups of your iPhone, however these can store corrupted files, and are not best used in a situation like this. -For further information on BACKING UP your data by syncing, THEN restoring your iPhone, follow this Article: http://support.apple.com/kb/ht3828

ya..it's possible..

You can only upload music to your iPhone via iTunes.
First, open iTunes, go to File menu and click on "Add file to library", find the song you want to add and click "ok"
Now the song will show in iTunes. Do this for all the songs you want on your iPhone.
Once you are done, connect your iPhone to your computer. iTunes will recognize your iPhone. Click on iPhone, on the left hand side of iTunes. On the main screen you'll have tabs for your iPhone such as "Information" "Music" "Applications". Click on the Music tab.
Select "Syncronize all music" in the Music tab.
Now on the right hand side in iTunes, you'll see a button "Apply"
Wait for your iPhone to syncronize with your iTunes.
Done!