(a) and (b) can be solved by WineHQ providing its own distro-neutral, run anywhere binary packages. This isn't hard as Wine is generally excellent at running on different peoples machines from the same binaries - after all, CodeWeavers need it. I think a nice installer for correctly built distro-neutral binaries for Wine would go a long way towards cutting the number of non-developers building from source down to zero.
I don't think we're doing too badly with the current packages -- over 85% of people go for them. Having a distro-neutral binary packages would be good, and it may shave off another 5% or so of the people who do go for source downloads.
The main problem however is that Wine is rapidly changing, and there is a need to build from CVS. No amount of packaging the official releases will solve that problem. But a distro-neutral might, because it makes it feasible to provide automated nightly build on SF, just like we do with winetest. Such a package can take care to avoid conflicts with already installed .rpms, etc., stuff that wineinstall is doing right now.
So, what about a autopackage package? :)