I have a feeling this is what we will end up doing. We are doing a park a day and HS is our last day. My guess is we will be tired so will probably just go and do the rides and muppets a few times, eat lunch at sci fi drive in and then leave to go rest at the hotel and maybe be back in time to catch 5:30 kickback meal at Drury. We kinda wanted to see the first night of the Jingle Bam but waiting around till 8 or 9 might be a stretch to find things to do and not be wore outYou could combine it with a resort/rest day. Spend the morning, early afternoon at the pool, then head to HS for the rides you enjoy and F! or Star Wars Spectacular.
Yes, I think you're making a mistake. If you said you always went before, the only "ride" that has closed recently is GMRR. The other things that disappeared were never really used much anyway. If you don't like the rides that are still there, then don't go. But I'd go just for RnR, Star Tours, TSMM, ToT...even if I didn't like the shows (which I do).