Credit Card Programs - [Targetted]20,000 flexpoints offer

Today I received an offer for 20,000 flexperks pts. with a $500 purchase. I believe this to be a very good offer. I also received a United Plus 50,000 mile offer plus 5,000 for authorized user and 10,000 annual spending bonus. question: I just got a Priority Club a couple months ago. Credit score is very near 800. Should I apply for both?

The UA is a good deal. Unless you have most of the other good cards out there I would research the other possible bonuses, as 20000 flexpoints is far from a great offer

Just stumbled across this incredible promotion today:

http://www.flexperksbonusoffer.com/ntl/

"Apply for a FlexPerks® Travel Rewards Visa Signature® Card issued by U.S. Bank* between 7/27/2012 and 8/31/2012 and you could earn bonus FlexPoints every time Team USA wins a medal at the London 2012 Olympic Games, courtesy of Visa!

We’ll start by giving you at least 17,500 bonus FlexPoints – but there’s no limit to the number of bonus FlexPoints you can earn. And all you need to do is spend $2,500 within the first 5 months and the FlexPoints are yours!"

I ran the numbers on the current medal count and it was around 19,000 FlexPoints, but the Olympics aren't over yet!

Question: I signed up three weeks ago for the in-branch 17.5k offer, also with $2500 minimum spend. Do you think I could ask to be matched to the Olympics offer?

I already have a flex perks visa signature. Does anyone know if I can churn/ apply for new card without closing the old one?