A few Questions

So I am going to be making a costume and there's some things that I'm a little confused on.
First of all I'm making a Magnadramon (Digimon, pictures below) costume.
Second, I plan on doing a dropped crotch (is that what it is called?) and using minky for the suit itself.

I searched through the memories for dropped crotches and didn't find exactly what I was looking for so I'll ask here and hopefully I didn't just look right over it. Anywho, when one is doing a dropped crotch:
- Do you have to walk any differently?
- Should there be stuffing inside of it so that it holds its shape or should a thin slab of foam be used so that it doesn't just look like a big flab of 'skin' or whatever?


As for minky, does anyone have any tips when sewing it? Should I double sew it, use a certain stitch, specific needle, specific tension?

I've tried to make a plush from it once and it didn't really work out all too well. I used just a regular multi-purpose needle and I don't really know what to set the tension to and all that. Of course, it could just need to be serviced.

I appreciate any and all answers/comments and I thank everyone in advance!

Here's a picture of Magnadramon: