If you ported your number in from T-Mobile, that *could* explain the problem with the text messaging - it can take several days for accounts to work properly, consistently, after a port from another carrier.  Four days should be enough, and hopefully it will get better.  You can try removing and then re-seating the SIM card to re-connect with the network - that may jog things so the y work better too.

As to the alarms, that would be a function of the phone itself and I don't know what could be the issue there.  I know this is a "basic" question, but did you specify AM for the time?  I know I have set calendar events to the opposite of what it should have been without realizing it....