1) As far as I know, if there's a limit, it's very high, my harlock Arcadia uses about 30 maps, I don't think any regular model will use up to half this...
2) it's set up in PCS, but I think you also have to make some submodel for it too... really not worth the hassle, if you ask me (I've been told it really was not easy to make them)
3) yeah, definitively a model. it's a subobject ( just like a LOD or a turret), called shield. It's the only subobject you can add w/o a modelling program tho: you can import a shield mesh from any other existing pof with the latest version of modelview. What is left is just to pick up one of the good size and shape
