We've been on the Island a number of times and never found any of the problems you describe. We're also leaving shortly for another Island Princess cruise next week & made notes of all the problems you've outlined.
It does sound like your missing the ports gave you a sour opinion of the whole trip. As far as getting to the show lounge 1 hour before and not able to get a seat? This sounds a little far fetched to say the least or perhaps you couldn't get certain seats like center stage in the middle of the lounge? I often get there early myself and there always have been seats 1 hour before. IF you show up 10 minutes before show time then it's understandable.
Like I said, we'll see how it goes and I'll be sure to report back with our opinions in mid Dec.