Hey there!
your
HQ choice is solid
Tact squad 1 is great,
ML for range, flamer for short range, rhino for transport. - good
Tact squad 2 is missing a rhino. other than that, setup is good.
Termie squad is good. i think the assault cannon is 40 points? dont have my codex on hand.
Dreadnought is also good, like i said, i dont have my codex on hand but maybe a rileman dread is a cheaper setup. (thats 2 twin linked auto-cannons)
I'd take the assault squad away. They have the same stat line as a basic tactical marine, and the only real bonus is the increased movement. If you drop these, you can take a rhino for your second squad and maybe a land speeder.
Anyway, hope this helps. have fun