I do keep the agitation to a minimum - I think that's what is hard on an item.
I see no reason to block them when - so far - opposite sides have ended up to be the same length - and the corners are square.
I do wash them because everything has been handled a lot in the process - and I did have cats - who participated in the making of the quilts.
I'm also a bit of a fanatic about how the grain lines go. I like them either parallel or perpendicular to the edges of the quilt.