I agree with Momtored, save your stuff for a year. Pack it up in a box, put it somewhere safe, then wait a year. If after a year you never miss those things then sell, trade or pay it forward. There were many things I got rid of, then 2 or 3 months later went looking for them.
My way to thin my stuff is to actually use it. I made a bunch of Halloween cards Saturday (I always wait until the last minute) and was so happy because I used up almost all of my mini glue dots (who knew they worked so well on ribbon?) I used up all of my orange buttons; I needed orange ribbon but had none so I used my paper crimper (something I had been thinking about getting rid of) and orange paper to make do. I also used up 2 sheets of DSP, which I hate to do because I love it so much and am terrified that I will never find another pattern I could possibly love as much as the one I just cut up, even though every time I go shopping I find DSP that I can't live without.
Also, if you have a bunch of one thing trade half of it for something you really need. I read you wanted to get rid of some of your glue items, that would be a good thing to trade. Maybe for some cardstock, I have 2 reams of white....