i've found small squad sizes to be pretty harsh against
IG, but if they are in rhino's its not too bad, so long as they dont all get popped on the first turn (
bl on that game
btw).
Depending on the mission, the DP may also deepstrike (one of the reasons for all those icons!)
Icons only guide teleporting and summoned daemons, not jumppack/winged models =\ its a shame but ah well
Havocs are likely to be riding in the Chosen Rhino (Or I may just give it to them, I havent decided) - aim is to get them to the middle of the table and climbing the tall building
I'm a bit dubious about a squad of Havoks climbing a building in the middle of the field dude. You want those suckers sitting back pegging shots at tanks. They don't need to sit in the absolute best position on the field... in my experience, they get shot less that way. If you have them tucked into a nice spot of cover with a good view, they will still be spitting
AT shots at tanks/chimeras, which im going to assume is why they have lascannons/missle launchers. sitting in the most premium spot often makes them lovely target for leman russ etc shells, but in a decent position (remember they are space marines, plenty of decent positions for the tough little buggers to stand and fire happily), your opponent is going to chose between a bikesquad with meltas, a laspred, and the havok squad if he wants to keep his tanks in one peice. And i would probably hit that bikesquad over the havoks.
You seem to have a solid plan for what all these units should be doing and what they will try to achieve, but i'm not sure about the summoned daemons. I'd be more happy with more marines. I'd probably swap out the thousand sons too, but i like my armies fluffy so nurgle+tzeentch doesn't feel right, and against guard i'd rather have another zerker squad/plague marine squad.