I say tint because it is the season and tint adheres better IMO in the summer or spring. As for the other, I don't know what speakers you have. I waited almost 2 years before installing my system that I already had (and was collecting dust)! I just had to save up for all the wiring and such.
I would say to tint your car if it is really sunny and hot where you live.
The short shifter - well that could come next I guess. I would however suggest new speakers IF your current speakers are blown.
No mazda owner should have to endure blown speakers. -- that's just cruel.