Great job by those above, for your other questions;
The squeegee will also give you the handle of the anti-security blade, mojo-skywalker on ebay also usually has the replica Michell Engineering Stylus Brush rods used as the anti-security blade rods. I cut the blade part out of 5mm. thick pressed board using RafalFett's template.
Lots of folks use foam rubber or similar for stuffing their pockets, and I've redone mine from the old socks I used at first. That way you can cut it into shapes so it looks like you have actual things in there, and I've got a bit hollowed out to hold the speaker from my helmet mike and a spot to hold my wallet and car keys.
You can go overboard with weathering, so be careful. If you do, sometimes you can wash it (either machine or by hand) to scrub some out. I used acrylic paints (brown, black, tan, and a bit of red) from my airbrush (but spray paint should work fine as well) onto wet fabric a little at a time, let it dry, then inspect it in full sunlight. I went through that for or five times before I thought I had enough (but not too much).
Same method for the flak vest, spraying a bit in the areas not covered by the armor pieces, especially under the arms and around the collar.
Over my chest display I have a bit of smoke-colored plastic, usually used for tinting your car windows, but I've seen some folks saying it should be a red-colored piece. 501st just requires something translucent.
I have a woodman girth belt, and I just rinsed it with water a couple of times, but haven't really added any weathering.
Hah, good one L3 -- I type too slow!
