Well, as you might guess from the signature, I'm a huge fan of the tervigon...
1) I'd also go with command - you have a (slightly) higher chance of a vaguely useful trait, which is about all you can hope for.
2) My army is constrained by the models - I use Crushing claws on (HQ) Alpha Tervigons and Scything Talons on (Troop) Brood Tervigons so they're visibly distinguishable. But I concur that the claws are probably more worth their points now initiative is irrelevant, and a sizeable number of extra attacks means access to one or two more smash
attacks - which can save your neck against something like a dreadnought. I take Regeneration
on the Alpha Tervigons because, whilst it's still not that great as an ability, if it can save you from a Warlord Kill, it's significantly
more worthwhile. I'll quite often find my tervigons in a fight more, and that ability to challenge Johnny Powerfist makes squads suddenly more wary of the big bug than they were.
3) Even in kill point games, spawning tons of dudes seems the way forwards. My lists pack 4 tervigons in 1,000 points and there's a very tyranid psychological impact when your opponent looks across the board and sees you spawn more models than he managed to kill in his last shooting phase. Seeing your deployment zone flooded with a literal tidal wave of chitin is genuinely quite unsettling.
4) Overwatch and precision shot do indeed make stinger salvoes nice - never forget your ability to snipe commissars, exarchs and apothecaries! - as does the ability to fire it at flyers if needs be. More importantly, flinging short range large blast templates around in the vicinity of many small guant units seems like a recipe for serious friendly fire issues. Mind you, I never did have much luck with scatter dice.
5) I've just been sticking with Catalyst
- Feel No Pain
is superb now it stops a significant chunk of plasma guns and power fist blows. After my Warlord survived a strafing run from four nightwings with na'er a scratch thanks to that ability, I'm quite happy where I am. I will happily concur that Iron Arm
is freaking awesome for tyranids - I think the power is perfectly balanced for S/T4 psykers but swiftly reaches 'what the actual krunk?!?!?'
status on a monstrous creature. My main complaint is simply that it messes up my nice 250 point block units! The Swarmlord, however, will be taking biomancy a-go-go. The ability to pump Iron Arm
simultaneously is nothing short of ridiculous.
If in doubt, refer to the Universal Tervigon Strategy Guide: