Very long layover at KIX / Osaka Kansai airport
I'm flying BKK-(JAL728)-KIX-(JAL60)-LAX in J. There's an 11 hour layover in KIX, 06:30 - 17:30.
I had planned to get out and do a little sight-seeing. My Japanese friend has summed up Osaka as: "has a twenty-year-old castle and a bunch of office buildings".
How long will it take me to get in to town from the airport? What time should I head back to the airport to be safe, given that I'll already be checked in?
What is there to do in Osaka? Searches so far have shown up only really "eat", and "Visit Spaworld", allegedly home to "ONSEN FROM AROUND THE WORLD". Would it be practical to get the train somewhere else (Kyoto?), or will I be cutting it a little fine? My flight arrives just before rush hour, and leaves in the middle of rush hour - is that something that should worry me for getting the train (or a taxi?).
I've read a single review of the lounge in Osaka, which suggested it's dreadful. I'm OWE - what are my options at KIX? AFAICT, it's just "Japan Airlines Sakura Lounge - Wing". Is this accurate? Is it really so bad?
Finally, all four of my sectors are on a 787. It looks like the seats are "JAL Shell Flat NEO". Is that right? I'm 5'11 and broad - am I likely to be comfortable?
Sorry for the wall of questions, and thanks.