To be honest, I’d calculate in the cost of upgrades/transports before thinking about adding more units.
You need to make sure the bodies you have on the table have the tools to do their job before adding more on. To be honest, the command squad might need to get the axe just due to points.
I run a battle demi co at 1,000 points. 3 full
tac squads in transports, 5 man assault/
devs, bare bones jump chaplain.
Your 1st company TF is probably going to be about 500 points, and that’s footslogging the terminators. 750ish if you take the
LR.
Calgar and the
HG are probably going to rack in at 400-500 points, depending on how big the squad is, and upgrades.
The dread and command squad with transports is probably going to be another 400 points.
Everything you have listed would probably clock into a 2,500 point list, with gear and transports. Now you could shave some down by using minimal 5 man
tac squads, and dropping the optional choices. You can also do things like swap the assault squad out for an attack bike, or cheep speeder. Or just collect and paint it all and swap units around as the mood takes you.
As you stated in the original post your goal was a 2k list, you should probably stop.
But other things to add:
Sternguard in a pod are quite good. Could sub in for one of the other vet squads, or just add for larger games.
You might consider an ironclad dread instead of the venerable. Less shooting, more rending. Also AV13 is significantly tougher.
Librarian conclave. They can add a lot of juice to your army. Either concentrated together for massed power, or spread out to disperse buffs.
10th company TF. Good, low cost, auxiliary formation. Can be fun to infiltrate homers for things to
DS onto.