Been a while since I was last in Vegas so cannot help you with the Triumph shop but I can help you with a few casinos or get married in 5min wedding chapels.
I'll 2nd RKTNMYPKT. Freedom Cycles is a pretty cool shop. We popped in there last year and discovered their bike rental program. They will rent Tigers, Bonnies, and Trophies (and I think Tbirds). Good people.
You can expect to run in to a mitt full of construction and concrete guys as the World of Concrete trade show (yawn) is on next week. This weekend is the setup weekend. The reason I know this is because I will be there setting up for the 20 somethingth time. I know it's a popular spot, and somewhere one should see at least once, but if I never had to go there again I'd be happy (no offense meant to any LV residents we may have here). The Super Bowl will be on just about anywhere you go so it won't be difficult to find that.
As for bikes, I'd be curious to see what it's like to rent a Triumph. I rented a HD last year and can't say I was a fan. There are many many places to ride to though if you were planning to rent.
If you can, get out the the Dam and do a tour of it. Also death Valley is worth a day out. You can also toddle up to where they blew up a few atoms back in the day. If you are real adventurous, Area 51, if it really exists, is just up the road too.
I was there last week too. I was lucky enough to get the Monday off so rented a Thunderbird from Freedom Cycles. They were actually closed (Sunday and Monday) but, much to my surprise, a lovely young lady by the name of Tiffany, opened up just to get the rental out. Rode out to the Valley of Fire and back via Lake Mead. What an excellent way to spend a day. Not to mention I missed the foot of snow e got at home that day