i only plan on making the required amount of blocks - if i don't like how one or two turned out only then would i make new ones.
as for guidelines, i stick to the rules and prefer others do the same. so the size should be correct, the color scheme should be adhered to, and if the fabric calls for 100% cotton washed thats what i provide.
i don't mind if points or HST aren't perfect - thats part of quilting and some people are beginners and others aren't - i love the imperfect blocks and much as the perfect.
i was in a swap that called for 100% cotton LQS quality and i rec'd back 3 blocks that were made from t-shirt fabric.
i would have preferred the swap host have sent those blocks back instead of passing them on since the person clearly didn't follow the rules.
i've come to learn, from doing swaps, its more important who the host is then the experience or perfection of the people in the host.