I just want to make sure you know that if you're trying to get mileage out of your locator beacons by using ate of infinity, you should expect people to argue with you that
GoI is not a deepstrike attempt, and therefore cannot use locator beacons. If they do, point them to line 7 in the
GoI rule, and explain that, in fact, the rule only says that it "uses the deep strike rules" for deployment, but on line 7
GoI is refered to as a deep strike attempt. This will probably get you mileage against other players but will likely do you no good in a more competitive setting such as tourneys.
If you're going to drop the scouts (don't see why you would... 100 points for a mediocre shooter that scores is still pretty good), then you need a backfield scoring unit.
tbh, scouts are great at this, so I wouldn't drop them.
You really need to decide if you're going with a mech or deepstrike army. It is VERY hard to make a list that maximizes the qualities of both, and this list hasn't reached that lofty goal.
Personally, I believe that mech armies are easier to use. They're more predictable for the user, and a lot more forgiving so long as you give them cover. Drop pods require that you know what you're going to do ahead of time, which is something that a lot of people think they're good at but realistically aren't. In addition you never quite know when the second half of your pod are going to come down... which can be extremely aggravating.
on to the real advice:
Neither of your
HQ choices do anything for you. A good
hq either gives you a decent army wide buff, a great localized buff, or can kill everything it comes into contact with. Neither of your
HQs do this.
It really does seem like you're going for a Drop pod army however... I don't really know how to do these lists so I'll bow to the advice of more experienced players but 10 man sternguard squads with lots of combi-melta that combat squad are something you need at least one of in your list.
your fast attack should also have speeders with heavy flammer
MM, they're a lot more durable than they seem on paper (at least against anything not hydra

) and they have two really good guns.
If you want to keep your locator beacons, then use them! Hammernators could give this list a lot of oompf
Aside from that:
Vanguard are okay, and can be good with shrike and locator beacons
the best pread is auto turret with twin las sponsons, accept no substitute but if you have a drop pod army.. you might not need it
if you want lots and lots of melta and flamer goodness, then just go with vulkan.