As somebody else said, how would anyone know if it was from LQS or not? As long as it's 100% cotton, go by feel, then wash or not as required by a particular swap. The first quilt I made - well, finished - was of fabric purchased at Joann's. I didn't even know about LQS's then, lol. It's probably almost 15 years old, and is used a lot as it is in the family room. It's been washed a lot and only one of the fabrics has faded at all.
Personally, I've been very lucky as far as bleeding. The only thing I've ever had bleeed was a Debbie Mumm Christmas fabric. Fortunately, I did do a test before using it. So much dye came out, I thought it'd be pink by the time I was done with it!
Sometimes you'll find a swap that says something like, "beginners welcome." That'll help you to know that there's probably a little more leeway given in block quality - although you should always do your best. Everyone learned sometime, it's just that some folks have been learning longer than others. The ones who really think they know more than others probably don't know as much as they think!
Pets - I am down to one cat, and he never climbs except to the windowsill. He gets brushed every day, so not a lot of hair around. That said, I still understand that some people would have to decline b/c of allergies. I have heard of remedies for smoke odor, but am not remembering what it is right now. Like some others, I really dislike that smell.
It was interesting to run across this thread today. I just spent a few hours tidying up blocks from a swap 3 or 4 years ago. It's a Jacob's Ladder done in white and 30's repros. Not sure what made me participate, it's not a combination I love. I'm trying to expand my horizons, so to speak, so bought some 30's fats and wanted a scrappy look. Anyhow, four of my blocks were returned for a flipped seam and one b/c I'd flipped a corner 4-patch. Honestly, if I get blocks w/ a flipped seam, I just fix them, no big deal. The flipped 4-patch, however, I have to admit was a no-no. Well, they're all fixed now and later today I'll be working on laying them out. Two of them did have an interesting hair or two on them, lol, not from a dog or cat...
I haven't yet participated in a swap here, but do occasionally look at them. Just haven't wanted to commit yet. The last time I made a commitment to swap, I was the one who fell through. Good reasons and all, and everyone was very kind about it, but it left me feeling awful! After the problems that caused me to drop out settled down, I offered to send my blocks, although they would have been very late - or fabrics in their place. I'd already purchased much of the fabric needed for the blocks I was to send, and some of them were not anything I'd use myself (not my colors). Only one person responded to me, which made me feel like they were upset with me. No swaps since then!