Is it possible to load an item through PSA, but without using it? For example, let's say I want to have the Star Rod always attached to Jigglypuff, but I don't want her to use it. I only want to have the model in her hand.
I've never used PSA before and couldn't find an answer.

Just drag an unedited pac file on the AIS. You don't need to extract anything from the pac to convert it into a dae.
I've uploaded my AIS, maybe yours doesn't work:
http://www.sendspace.com/file/q5gddj

Or I could convert the file you need into a dae file. You just need to tell me what model you want.

I got the texture problem fixed, but I still don't know how to attach the hat to Jigglypuff (and maybe resize it). Can anybody help?

Are your files unedited? As far as I know, you need an unedited pac file to create the dae. At least that's how it worked for me.

I recently got back into Brawl and now I'm trying to replace Jigglypuff's green hat with another model, but I'm having some problems.

The first problem is, that the hat is just lying around in the middle of the stage and isn't connected to Jigglypuff. I used the bone adding tool to up the amount of bones to five (the original model only had one) and named the bones the same as Jigglypuff's hat bones (TopN, AttachN, CapJa, ...) . Before someone asks, the model that I'm trying to insert was already a mdl0 file.

My second problem is, that the colors are acting wierd. The original texture of the model had a palette, but whenever I try to import it, the game freezes. I made two versions, one where I set the palette data in BrawlBox to true and one where I set it to false.
The model with the palette date set to true flashes in random colors:
http://img5.imageshack.us/img5/571/al1003231900.jpg (on SSB64 Battlefield)
http://img262.imageshack.us/img262/7100/al1003231901.jpg (on Pictochat, after using Rest)
http://img202.imageshack.us/img202/474/al1003231902.jpg (on Pictochat)

The other model stays red the whole time:
http://img547.imageshack.us/img547/7663/al1003231906.jpg

How can I fix these problems? Help is much appreciated.

No offence taken, but you what, I don't care. I never said that they were good and I was just offering some help here.
Just so you know, I don't like competing with others, especially not over something that was done during my free time, while I was bored.

I made some textures you mentioned already some time ago, here's the link if you wanna see:
Link
I don't know how useful they'll be to you.

Pretty sure it was this:

Back then, when there was no BrawlBox, only ASH. I kinda miss the old days.

That, and nobody around here will get the "joke" used in the fourth picture you made for this hack.

I get it. Do I get a cookie now?

Really nice work, I downloaded your classic Pokemon Trainer Red a while ago.
Ya know, I still had the old Koga texture on my SD card. How long ago was it when I helped you with him? Definitely a long time.