Space Marine brigades struggle quite a bit to fit in the necessary tools to be a TAC-style list and complete game-objectives. That being said, you have taken a few good units to put you on this path, so here are my recommendations.
Land Speeder Storm: I hate to be the bearer of bad news, but these are just hot garbage. Over-costed coupled with the -1 to Hit penalty for moving and shooting applying to vehicles means these transports are massively over-costed. Scouts just don't pack enough of a punch to leverage the open-topped rules, and the vehicle doesn't benefit from out CT either, which further de-values it.
I would drop both transports.
The scout sergeants with Combi-weapons should never be in range to be used in tandem with Snipe Rifles (Your snipes should sit backfield and camp objectives in your deployment zone, and Bolter-scouts should be infiltrated up on closer objective - or as screens).
I would switch both Combi-weapons to Snipers
The Grenade-launchers on the Scouts don't give them any real extra punch, and they are better served to carry Shotguns. Also if you give the Sergeants Storm Bolters - that will increase their efficacy for that output of shooting greatly. These are great units that output a ton of firepower for very little cost.
I am a big fan of the Damocles-pattern command Rhino, very fluffy!
Now, with what we cut/changed, that frees up a little over 300 points. I would use these points to get some real heavy weapons into your army.
Options are Dreads, Devastators, or Preds.
I am a fan of the first and second categories, since they leverage our CT. That being said, you don't have a lot of good targets for your Lias deployment, so I would probably lean Devastators in your case. You could also swap out on Scout Bike squad for a regular Land Speeder with dual Multi-Melta to continue use of your telemetry stratagem.
I would probably take 2x Dev squad, I would also probably cut one Whirlwind and purchase a 2x Dual Autocannon Dread to hit transport-style units.
I would convert your 2 5-man Sternguard into one 10-man and SFTS that unit
I would use your Lias deployment on himself, both devs, and your LT so you can drop them in your DZ on your first turn accomplishing two things: Getting superior fire lanes, and 2 making those units immune to an Alpha Strike from your opponent. This is probably the best use of Lias in the new Deep Strike beta rules.
Good luck, and welcome back to the Raven Spire!