I would drop the stim injectors, the units you have them on are already 2+ saves and they're overly expensive for the save you get. Plus both can
JSJ so you should be able to keep them relatively safe especially the riptide with
IA has crazy range. If you're worries about his gets hot rolls you can take an earth caste piloting array for 30pts that let's you reroll failed gets hot at the cost of 1
ws. I would also drop the VT off him as its expensive and with the skyray marking any fliers you shouldn't miss.
I would also move the bodyguards to the squad with 1 suit in it so he's not behind enemy lines all alone and have the commander join them and if you're using them for tank hunting I'd go
FB/
TL FB, and target lock.or
FB,
FB, flamer... That would get you 2 tank busters a suit and a flamer for overwatch plus the gauntlet. I personally also like having the system jammer as well. I've had it save my bacon a few times having a squad of enemies with gets hot is nice and it's only 2 points
I'm also a huge fan of Fire Warriors so I try to max them whenever possible and if you're gonna go less fire warriors I'd suggest an ethereal to give you a bit more fire power from smaller squads. The Fireblade is nice but he's limited to 1 squad
I can honestly say I've never used piranhas but I'm not convinced 1 is worth running (I can see a full squad of the. Doing some damage).
All this is still just my opinion and I'm still relatively new to tau so take it with a grain of salt