I have to disagree with programs not having 64-bit compatability. I've seen them from Stardock with 64-bit processes running... (wbvista.exe mainly.) Considering most of them don't need to be constantly running, there's no need for a 64-bit version.
As said above, 7's boot screen is fine the way it is, no need to change it. As for other programs, as a precaution I've always googled the program to make sure there aren't compatability issues with Win7 before downloading it. A couple extra steps, but saves a bunch of computer headaches in the future... (a couple are common sense; you wouldn't install TweakVista on 7 or vice versa for example)