I tried iheart.com in the desktop version of Dolphin HD and it was fine except that when I zoomed as you suggested, the short menu on the left side of the page stayed no matter where I moved through the page. I am using Flash 10.3. When I tried to look at the mobile version of the site, a screen came up saying that I had to install a separate app, which I didn't try.
For me, wasn't much of a problem.
BTW, there is a Dolphin add-on called "Desktop Toggles" which switches from desktop to mobile versions of the browser. 99% of the time, I use the desktop mode on the VTAB, but once in a while the mobile version works better.
I'd like to know if anyone has done a reasonably thorough study of Flash 10.3 vs 11.1, and, if so, what are the benefits/drawbacks to each?
Answering my own question, I went on Adobe's website and found the release notes for 11.1. According to those notes, 11.1 has not been optimized for or tested with any browser except the Android stock browser. The notes say that most of the changes in 11.1 are security-related. I'd say that, if you try 11.1 and are happy with it, that's great, but, for most of us Dolphin users, you might want to wait until Adobe gets around to making it work with Dolphin.