OK, this may seem harsh, but against all comers, that list sucks.
You have no anti-tank (well, no reliable anti-tank anyway, powerfists can get lucky, but you shouldn't rely on them), and have gone all out on the worst upgrade available to you.
Here's a breakdown:
HQ:
If you're going to drop-pod, a Librarian is far more suited to the role. If you're insisting on the Captain, give his command squad 2 melta guns and infiltrate, maybe go for the CC elements of the command squad (champion and veteran sergeant), but only if you have spare points.
Either way, the flamers are not worth the special weapon slots. In the HQ squad, go for melta, it's nasty when you land, and if you need to try and assault something it gives you those lovely extra shots before charging.
Troops:
Loose the sniper scouts, if you want scouts then try out a CC squad (large numbers, frag grenades, veteran sergeant w/ power fist), or missile launcher squads. Sniper rifles are just not good enough to be worth that many points, especially when you probably won't be coming across many monstrous creatures, and if you do they will be easily able to stay out of LOS (I'm assuming you're using cityfight rules).
Those tactical squads need melta or plasma. While flamers seem nice, especially in cityfight, unless you only play against orks/eldar/guard they are going to be next to useless.
Overall, I like the style of the army, it should work nicely in cityfight (assuming you make some of the changes I suggested). All infiltrating/drop-podding is powerful and forces your opponent to think very carefully about thier movements, but that doesn't mean you should be lazy. You have to make sure that your troops remain supported, and don't get cut off and taken apart as and when they arrive.
I would loose one squad of scouts, change the other into a CC squad, change the weapons around in the SM squads, and add a dread in a drop-pod. This should be aproximately similar points, and maintains what I see as your theme.
Again, no offence was meant. I hope you understand that this is not a personal thing, I am just trying to help you make a better, all purpose list. The one you have is probably very nasty vs. hordes, but it would be a walkover for a MEQ player.
Good luck,
-t.