direct sms to email and aim, messnger problem



I hope I can get my issue resolved here.
Im using my brothers old HTC Inspire 4G (ATT branded) that I started using when I switched to MetroPCS 3 weeks ago, but Ive been having a few issues. My Previous phone was an LG Shine. (yes, very old)

1- Could receive a picture msg but not send one. Standard txt msgs were fine. (Fixed with updated APN setting from the operator)
2- Not able to initiate a sms or mms direct to email. I can reply to an email when they send it to (number) but I cant send one direct from my number.
3- Cant receive messages from aim or yahoo messenger. From aim to my number, not from user to user.

Number 3 is my biggest issue. I have a girlfriend and family that go to mexico often and they communicate often by logging in to their aim or yahoo accounts and typing in my phone number.

I know that 3 is something that works since my brother is also on Metropcs on the lowest plan $40 with no additional options. I logged into my aim and yahoo account and sent him a text. It worked flawlessly.

I know I can add the apps but I like the fact that they can reach me by entering my number or if they use my user name, it would redirect everything to my number.