Replace jedi starfighters with fighters. Fighters are better for a few reasons:
a) They are built out of the airbase, which costs carbon and wont require you to change your economy around much like you would for the 550ore-fort. They also build faster allowing you to hit earlier.
b) Fighters are quite a bit cheaper
c) Fighters cost less
d) You can afford more airbases
e) Fighters fire faster.
Geo rushes are a nice suprise and easy to rustle up. I did a late one in a LAN game the other day, we were havin trooper wars, got to t3, waited a bit, and naturally he didnt expect any air attacks, so i made about 4 geos and really hurt his economy. Even thought i still died it hurt his economy a lot =p
Fighter raids are the best alternative to strike mech raids. Sometimes your enemy may be ill-prepared for it, or over-prepared for a mech rush.
Galactic empire has cheaper air; they may be the best for this.