Ok, so I'm working on my mod, and I've got a problem.

I'm trying to edit the Lift-off/Land feature of the Terran buildings, to work for my new factories: the Recycler, the Unit Factory, and the Armory. Here's the rub: I want them only to be deployable on a geyser (not to be confused with a VESPENE geyser). I have the ani for a small geo-thermal steam vent (geyser) ready, and I want this to be the deploy point for factories like the Recycler (my version of the Command Center). What I want is for the factories to be able to deploy (land) on a geyser, and therefore become active. I also want the geyser animation to dissapear when a factory is deployed. Also, I want all of the MOBILE factories to be built at the Recycler rather than by the Construction Rig.

That brings up another question: I want the Scavenger to gather minerals, but not Vespene. I want the Tug to gather Vespene but not Minerals. And I want the Constructor to be the only thing that can make buildings. How do I do that?

Oh, speaking of minerals, is it possible to replace the Mineral Fields with large fields of Mineral Chunks, which the Scavengers could go and pick up?

Lastly, how would I make a cloak that requires no energy, but can be turned on and off, disabling attacks when it is engaged?

Anyone who plays Battlezone will know EXACTLY where I'm going with this...

I have little no to no idea where you are going with this, but that which I do have an idea about I will try to provide you an answer with.

Scavenger/Tug harvesting only minerals/vespene respectively does not work, to my knowledge.
Using FireGraft, you can remove the ability for a worker unit to be able to build buildings by removing the appropriate buttons and modifying the Dat Requirements of the buildings.
This will cause the worker unit to be unable to construct buildings.

Plug-ins may be able to help with transforming Mineral Fields into large fields of Mineral Chunks, but presently, due to an absence of a create unit function, it would require a lot of work and memory address finding.

Cloak can be modified through FireGraft to disable energy drain. DAT editing can be used to take off the initial 25 energy cost. Plug-ins can be utilized to order detect any unit that is cloaked and has an attack order to stop. This is a workaround, and I am not sure if an error message can be implemented easily.

Not sure how to implement your first idea.

Workers that pick up powerups (including mineral chunks) will not drop them off at a command center to my knowledge.