1.
The blackberry brings its own software. You install it on your computer and once you run the program you can back up your phone including the messages I'm not sure if you can send them through bluetooth. I text a lot and this phone holds my texts messages from exactly 30 days ago and you can save them so im sure you'll have plenty of memory on the phone

2. Is there a way to set a short MP3 audio clip as the ringtone for this phone? Yes you would just plug it to your pc and view it as a massive storage device, you'll see a file that says ringtones this is where you need to save the files to in order to set them as ring tones. If you go to www.zedge.com you can create a ringtone from whatever song you want and you can pick the exact part of the song (it's free)

3. This Im ot familiar with. Sorry.

4. It's fast. I have no clue how metro can make it this fast without 3g. I was shocked when i first used the browser. I used to have the T-mobile G1 and the blackberry for metro is a lot faster!

5. I have not found anything I don't like. I loveeeee this phone. The battery life is great, receptions awsome internet is super fast, I get all my e-mails directly to my phone and all I pay is $66 a month (includes insurance). You can download applications for free if you google them you'll find tons of sites and the themes let you customize the phone.