Keep in mind that if your Devs are manning the ADL, you could lose use of half your firepower depending on what you're shooting at.
My thought process here:
T1: no fliers, no problem
T2: if fliers enter, interceptor means I'm not firing next turn and if they don't show up then no problem
T3: see T2
T4/T5: by this point my opponent has either closed in on that squad and I have other priorities or I've wasted what I need to waste and no longer care about snap shot-ing 4 heavy weapons.
Conversely, what I have considered doing is doing a ten man squad w.2x LC and 2x FML and CSing them so there's two heavies in each CS. That way the Flakk can man the QG and the LCs can do what they do, both with 3 marines as meat shield (yes, the sergeant is included in this even though he has a Signum). What do you think about that?
grab a 5man squad of Autocannons
This can't happen, ACs aren't available to SM Devastator squads.
Another option, which was never mentioned, is going with a Stormraven over the Crusader.
I don't feel like Stormravens fit in with IF, and the two that I have are most certainly staying BA oriented (one's painted, the other I keep in a drawer until game time because of how long it took to paint the first one). Also, with a LRC I have the ability to charge T2 if my opponent moves forward. With the SR the soonest that is happening is T3 if you Fly on the board...and really, why the heck would you not so early in the game and IF the SR comes in T2.
Back to the Tactical squads for a moment:
I'm torn on even taking a heavy weapon. I would really like to rely on other things to do armour damage, and leave my Troops to shred other Troops. I was thinking of leaving them all bolters and only taking a PG for the squad in case some TEQ/CC threat gets up in my grill. This means I'm never losing shots to Snap Shots on the move and I take the most advantage of Bolter Drill with the few guys with bolters. It also limits their effective range to 24/12", but hey. That's what the Rhinos are for. Thoughts?