I wonder if someone could tell me if this itinerary is acceptable as a single redemption or if as I believe is stretching the rules too far:

LON-SAT (could be via IAH, IAD, ORD,..) on 21/04
SAT-LAS (Via IAH, CLT,....) on 25/04
LAS-SAT 29/04
SAT-LON 03/05

If this is valid routing then what sort of tax will I be looking at for a Y redemption?

Cheers