Getting rid of excess fabric is easy for me. My guild does an annual sale and accepts donations of quilting fabrics - washed or unwashed, any size, any shape. They also accept donations of fabric and batting for charity quilts and cat & dog "cuddles" for the shelter.
Alternatively, and for anything that's not quilting fabrics, there's a local shop called "Legacy" that takes any kind of fabric donations (including UFO's) and also various sewing/crafting supplies/tools and they will sell it; the profits benefit the local senior center.
AND, then there's Linus project. My local rep is actually a member here, I've had the pleasure of meeting her in person, so there's yet another place to me to donate fabrics. (I haven't yet, but I should...I have some kid-friendly fabrics I could stand to let go of....)
I've been given fabrics a few times and I always tell them that a condition of me taking it is that I will take whatever I can use and then donate the rest. I've never had anybody think that was a bad idea or not give me the fabric - they're just glad to be rid of it and trust that I will do my best to get it somewhere where it will be used. Unless it's gross - I had to toss a big bag full of fabric because rats or mice had gotten into it and I wasn't even going to TRY to salvage any of that nastiness! It went straight from my car into the trash. Ick!