I must apologize for not responding to all these posts.
Thanks for all the interest.
1. The beer came out fine: no contamination that I could detect.
2. I must confess to being wasteful of plastic; in the confines of a small post-retirement condo, cleaning a five gallon tub is going...
One really nice thing about doing a 2.5 gallon batch:
you can buy a 2.5 gallon jug of water at the grocery store,
and when you're done you don't have to clean it: just throw it away.