Tim, I think all of the things you mentioned can be traded, but the person receiving the plant needs to understand what he/she is getting, so the trade is equal. If you want to know what the person is offering, ask. Is it a vip leaf (leaf with fuzzy nodule), a vip start (small plant with leaves), a small starter plant, a division, etc. If you are not sure what the descripotion means to the one giving the description, just ask.
Example- Bob in Ill. is looking for vips. I only have vip starts on my plants, but I offered them, stating they were very small vip plants. By that, they are newly growing plants on the end of the plant stems, but they do have leaves formed. They are not small plants freely growing in soil, nor close to budding and blooming. They are only a couple of inches in size. They should grow, but are not planted currently.
This is my gauge on trades. I look forward to hearing others' viewpoint.