I'm not into the partying or Casino scene, so I could be a bit off the mark, but I believe the best nearby bet for that is the neighboring town of Bregenz. Bregenz is on the lake and has a famous theater festival in late summer / early fall, and seems to be a fairly popular summer vacation spot for Germans/Austrians/Swiss who only want to travel a few hours from home. I believe I remember a lakeside casino in Bregenz. One caveat is that, since Bregenz is pretty much a summer destination, much of the nightlife might be meager or shut down in Feb./March.

Regarding restaurants, there are plenty of good restaurants with the standard German/Swiss fare, though of course you'll have plenty of that in Regensburg. The restaurant at the top of the Panoramahaus is a bit fancier, and fairly successful at pulling off the somewhat higher sophistication (In general, I find Germanic restaurants tend to fall on their faces when they try to get a little "uppity" rather than sticking to the basics). I once stayed at the "castle-hotel" in Bregenz (don't remember the name off-hand) and seem to recall that their promotional literature promotes the chef there as a special and well-regarded individual on the European gastronomic stage. I can't testify to his prowess from personal experience, as the prices at the restaurant there were well past my budget at the time.

If you're into Alpine scenery, the Austrian Alps begin just to the east of Dornbirn, but in my opinion the drive to the Appenzellerland (about 1 hour away) in Switzerland is more scenic.

You're also not far at all from Liechtenstein, if it would interest you to visit one of the world's smallest countries.

And if you want to ski, the closest resort would probably be Davos, about a 90 minute drive. Don't know how the relative dearth of snow in the Alps this year might affect the prospect for good conditions, though. There are a couple of Sheratons at Davos, but I'd expect that in ski season the rates would be multiples of what you'd pay at the Dornbirn Panoramahaus.