There is no reason to ever put a Praetor in any version of terminator armor. A Praetor already comes with Artificer Armor, you can give him an Iron Halo, and have all the bonuses without any of the negative benefits of Cataphracti armor- can't run, can't sweeping advance. Then you can add the Paragon Blade, master craft it, and give him digital lasers and he'll be great.
Flamers in 30K pretty much suck. EVERYTHING in 30K has a 3+- you are fighting marines vs. marines. Yeah, there is the Mechanicum that has a couple units with 4+ or 5+, but in general, everything you fight will be
MSU- T4, 3++.
The Legion Tactical Squads are only 10 models and "Plain Jane"? Always a good idea to give the sergeant Artificer Armor and a P-fist or Power Weapon. Dueling in 30K is a thing, and some armies have to issue challenges. Having a Sergeant that can at least swing before he is erased is a good idea. 10 Model Tactical Squads are easily removed from the game. The "Optimal Squad" for foot slogging is 15 models, Sgt w/ Artificer Armor, and some kind of power weapon. Sometimes melta bombs. It is critical that you use Apothecaries with a foot slogging squad.
The #1 threat in your list (to me) is the Support Squad with Plasma in the Rhino. Protect those guys at all costs! There is an over abundance of light anti-tank weapons in this game.
Love the Rhino's with Multimeltas. Not enough players realize the utility of a Rhino armed with a heavy weapon like that.
The Sicaran Venator can very happily exist without Lascannon sponsons. Just about anything you shoot with it's main gun will die. The Lascannons just add a huge over kill factor and are a waste of points.
You would be better off converting the Predators into Plasma Executioners. A "Plain Jane" Predator is, at best, a nuisance. Give 'em Lascannons, or Plasma, or something.
The Land Raider Phobos is pretty meh compared to the Proteus or Achillis. The Proteus is usually taken for the ability to take an extra
TL Lascannon (three
TL LC's!!!).
A huge weakness you have is no anti-aircraft. A Fire Raptor, Lightning, or Xaphone is going to rip you up. Might consider some form of Anti Air.
That's what I see at first blush. It's not a bad list, just inefficient. Every meta is different though, and this list might do well in yours. In mine... it would get slaughtered.