No problem at all, I won't say no, ever
If your device is not listed as compatible, dont flash it...bad things can happen when you try to flash a rom that is made for another device!
The rom I linked is the only one I found so far...didn't search real hard, but wasn't looking for other roms...just something that would help you with your mms thing.
Let it be said that I am not familiar with your device but some things are similar to mine.
I think the simplest thing to do is download that rom.
Double check the md5 checksum that is posted so you know it is a clean, not corrupt, download.
If you are not sure on how to check that, I can provide a link that better explains that. But in all my time of downloading stuff, I have not had a bad download (corrupt). Others have. So it is possible.
Make a nandroid backup in recovery. That is a snapshot of your phone's current state...like a game save...if anything goes wrong with the flash, your can restore your phone from that backup you made.
Once you have the rom downloaded and on your sd card, you can flash it from recovery.
Do you know how to get into recovery?
I know, alot of questions and alot to absorb here. sorry.