Incorporeal beings and Alternate Form

[DrMotives]

I was trying to figure out what happens to equipment or the lack thereof with alternate form, reading the rules seem a little unclear. While the PH says that incorporeal beings "are immune to being polymorphed" that's passive voice, and seems like it just means that an enemy caster can't polymorph them. Also Alternate Form has a number of differences from Polymorph, such as AF keeping original type & subtype, which PM sheds to assume the new forms type & subtype.
So does this mean that an incorporeal creature with AF will stay incorporeal whenever it shifts form? And does taking a humanoid AF make fake clothing, or would it need a bunch of ghost touch gear to wear in its AF? Ideally, I'd like a way for it to not be incorporeal when it uses its AF ability.

[Crake]

I was trying to figure out what happens to equipment or the lack thereof with alternate form, reading the rules seem a little unclear. While the PH says that incorporeal beings "are immune to being polymorphed" that's passive voice, and seems like it just means that an enemy caster can't polymorph them. Also Alternate Form has a number of differences from Polymorph, such as AF keeping original type & subtype, which PM sheds to assume the new forms type & subtype.
So does this mean that an incorporeal creature with AF will stay incorporeal whenever it shifts form? And does taking a humanoid AF make fake clothing, or would it need a bunch of ghost touch gear to wear in its AF? Ideally, I'd like a way for it to not be incorporeal when it uses its AF ability.

You are correct in assuming that an incorporeal creature using alternate form would remain incorporeal (as it retains the incorporeal subtype). I do believe I remember reading somewhere that alternate form (or maybe change shape, or possibly both?) could be used to change/create your clothing as well, though I'm not sure I can remember the source.