I hear you on everything here! My TA is the worst business person I have ever met - useless, stressed out (umm hello this is your job!), disorganized, unhelpful etc etc etc. Essentially I have done all the planning arranging, assisting guests etc. we used her becuase she OWNS the travel company my FI's mom work's part time at - NIGHTMARE. Our package flight is now sold out - yeppers - eight months out. So now we are looking at a second option.
In terms of rates, do not panic as this is totally normal and we went through the same thing this year and last year with FI's best friend who got married in Mexico too. We bugged our TA for 6 months - she kept saying 6-8 months before while in reality we got our rates in mid-January for a November 27 wedding.
When I look on line I can book trips up to December 17 of this year - I would guess that by May there should be rates appearing - ours haven't fluctuated much from last year or since they were first released!