be wary about the reaper launcher idea... as the launcher itself is not mounted, there's alot of debate as to wether or not you can move & fire. (being infantry carried, techniqually you shouldn't be able to...)
go with a fusion gun instead - more anti-tank power plus it's ap1 for either causing an easy wound on an isolated squad before you assault it, or else for taking a wound off of some big ugly gribbly monster!
i'd also work all your squads into even numbers for scoring unit purposes too... you can re-work your bikes from 2x9 into 3x6 strong squads. another scoring unit, and each squad is now smaller meaning it's a bit easier to hide them!
also, tank-hunter is a bit over-kill on the dragons... ap1 & 'melta' is more than enough to kill anything... (also note that again, tank-hunter would be useless against a monolith!)
finally, instead of the brightlance on the falcon, give it the eldar missile launcher... now it can fire on the move, but you still have a S8 gun to fall back on if the pulse laser is hit.
cheers!