...can... can I call in a drop pod to hit an enemy? Like.. if it actually hit it would obliterate the darn thing... right?
No, but you can call in a Lance Strike, for example.
It's meant to be fun. It's supposed to be fun. The rules are there to enhance and guide the fun, not make playing the game a chore.
If the players need to have a candyman GM to make the game fun, then we might indeed have a problem.
"Hey, GM, the game isn't fun to me if I can't request a Titan and ride on its back into the Hive invasion."
"Yeah, but the game isn't fun to me if you can; maybe look for a different campaign, buddy."
It's fun to make the player have to guess at mission prep. It's fun to watch them having to deal with the consequences of their choices. Conversely, it's no fun to imagine a bunch of Space Marines kitted each with Storm Bolter in hand and another basic weapon slung around the shoulder. That is not how Space Marines, even Deathwatch Space Marines, are portrayed as. On no illustration and not as minis. If you prefer it that way, fine.
Not in my game though. There's not even negotiating over that. What is permissible is storing an extra weapon or two per team in a Rhino, for example. Special munitions Drop Pod only if the mission requires prolonged fighting instead of a quick in-and-out. These are exceptional missions for the Deathwatch though. Normally, it's in-and-out. No sitting war.
My 40K Blog (essentially a Best Of FFG Forums):
House Rules, Rule Clarifications, Game Aids, New Creatures, consolidated official Deathwatch Squad Mode rules, 40K Tabletop to 40K Roleplay comversions, etc.