I've got 80K in Ultimate Rewards from Sapphire and 60K from Ink and 20K in United. And 185K in Amex

I want to travel from NYC to BKK in Feb.

A few questions- first, I am finding what looks like super incredible redemption deals on United's website. There are several 80K Business Saver flights available! It almost seems too good to be true.

Within Ultimate Rewards, the business redemption is 300K!!! Why would there be such a difference?

Also, the 80K flights directly on United's site are operated by ANA, Asiana, Thai Airways, Lufthansa, and Brussels. I've heard that United's business class is pretty bad, but does "operated by" mean that I'll actually be flying another airline's plane? And can you recommend any of them over the others?

Finally, the reward flights are showing 80K + $100 or so in taxes each way. I've heard that if I use the United Chase card, the fees are waived. I just applied for the United Business card, but they may be onto me, as they need me to call in. Same thing happened when I applied for the Ink. I have all the Chase reward cards but I have not opened more than 5 reward cards (from any institution) in the past 24 months. If I wait until the card shows up in the mail, it could be only a few days before I plan to leave. Do reward flights go up in miles the same way regular flight prices fluctuate?

Thank you for your help! It is a bit overwhelming just starting out.