No, landing troops don't trigger reactions as the unit is still classed as 'airborne' until the end of the current turn. They don't trigger a reaction until they carry out an action as a ground unit.
You can't use many psychic powers in reaction... bugs can counter charge, shoot or alarm screech. The only powers you can use are those considered shoot actions, then only if they aren't also considered pack or internal etc...
As for the drop pods.... it says all air units are treated as reserves.
So I'll counter that with: Can bugs take hoppers/ripplers as air reserves if they don't have attack orders? The air unit rules are in addition to the reserves rules, but are the air reserves taken out of your alotment of reserve units?
It's all numerical strength anyway, If it became an issue I'd just stick in a couple of neodog units to let everyone else drop.
