1) I would drop the command squad.
-It doesn't score.
-Has bad durability for its points cost
-Does not add much (if anything) to the army.
-You could have spent these points on another scoring unit.
-If you want a beatstick terminator squad to go with belial, then pt him with the knights.
- If you are walking so many units across the board, you might want to try and use the FNP banner instead.

2) Squad loadout:
- Using terminators for shooting is not an effective use of them, you want them in melee.
- CML/ Assault cannon are the undisputed best heavy weapons. (Unless you are using belial + HF squad perhaps). Plasmacannons are pretty poor in comparison.
I would get more TH/SS. They are the only thing that makes your terminators even slightly worth their price tag.

3) Base landraider???
- Who takes these things anymore. Almost any other raider would be better. Terminators are packing str 8 armour ignoring weapons, so leave the big stuff to them. They struggle with hordes, so get a crusader (or possibly a redeemer, if you like the inferior option).
-Also consider the Spartan assault tank instead. +45 points gives you 2 more lascannons and an exta hullpoint.
-No deathwing vehicle either?
-Storm bolter?!! The multi-melta is only 5 more points.

4) Also, only 1 landraider??
-Footslogging terminators wont end well, deepstriking them in is also incredibly risky, only belial's unit wont scatter, and dropping multiple scattering 250+ point units in one go has a significant risk. (also tau pie plates of intercepting with ruin your day).
-Consider a 2nd landraider. It will provide more cover, let the unit inside move safely up the board, and will also take some of the anti tank pressure off your existing raider.

6) Plasma cannon dreadnought - Why?
-One advantage of DA if that they can take multiple mortis dreads.
- For 145 points you can take a dreadnought with 2 TL lascannons which has skyfire and interceptor. I know which one I would choose.

I'll be really blunt and say that tau will ruin anybody's day. One raider is going to have to do since it does only leave 1600 points for the rest of the army and that's not a whole lot of points in the sense of deathwing. Deep striking terminator is it risky, yes but sometime you have to take risks to achieve a certain leverage against the opponent.