Hmm, where to begin HQ
Purity Seals are next to worthless, don't take them.
Give him a bolt pistol, the extra shooting is not worth losing an attack.
I don't think artificer armor is worth it, but some on the board will disagree (I'm looking at you Nathan
I don't mind it the load out except for the plasma cannon. This squad will need to be moving every turn in order to be effective (has to reach close combat really) so lose the plasma cannon and make sure everyone in the squad has bolt pistol + close combat weapon.
I like a transport on these guys too, perhaps a razorback at this unit size, although Rhinos are more cost effective for something that will be in the thick of it.
Give him a missile launcher instead of the close combat weapon and trade FC for tank hunter. He kills too slowly to be really effective in close combat unless supported by a very killy unit. Fast Attack
You can only have 5 bikes in a squad, so you need to split this up (or indicate how you already have, 3 squads of 4?).
I don't mind power weapons on these guys, but make sure to give the Srg's bolt pistols too.
If you are looking to tank hunt with bikers take 3 squads of 2 attack bikes with multi-meltas. Much more effective. Troops
Again not sure how these guys are divided up so make sure to separate by squads.
Flamers are not very useful on true gritted guys, take them out. As you want to maximize the amount of casualties you inflict before you receive the charge, where as with flamers you will normally need to move close to the enemy in order to get the jump with them. You could leave them though.
Melta guns again, same thing as flamers.
I like plasma guns in true gritted squads.
I would leave your vets with just regular bolters, the extra points on the other guns really aren't worth it. Combat shields are pretty useless too. As he will only really use it once he is the last one standing (it's not as if you will risk a 1/3 chance on a power weapon hit for example).
Also, make sure to give them all power fists. The hidden power fist is the single most important thing in making competitive space marines. Throw one in a squad and all of a sudden you have a dude who has ablative protection (the other marines) and cannot be targeted. These dudes will help you out every time they hit close combat.
Sniper rifles are pretty useless imo, better to use the points somewhere else. Can be helpful in a pinch, but rarely.
I think the list is okay as a starting point, but needs a lot of work. Any thoughts on how you will play it?
Also, make sure to let us know what traits and drawbacks you are taking.
Oh and Ryan is right, take the individual points out. It's actually illegal to post them.