Does anybody has a good suggestion how to change from the current state with groups? We are happy to have abandoned projects because a lot of users did not understand this concept. What tiny change we should do to make you happy and keep it right for other users, too?

The next 8.1 preview build will allow to skip such few common and expected dialogs.

You already can do that, e.g. by prefixing the pattern with a !, e.g. !*.png will not show any *.png file.

This already works: please use the Window | Commit Message view to write the commit message.

Sure, just select the "View all files of the selected commit" icon above the Files view.

This is old, error-prone SVN style. Usually, you have to get the whole working tree at the state of a certain branch. That's what the normal checkout is for. But maybe I don't understand why you need this feature (so often) that you propose a more direct way than the current one.

You should be able to check out every file in every repository state by selecting the commit in the Log, right-clicking the file and selecting Save As.

You can create a wrapper batch file (as diff tool) that simply passes just one (the second) parameter to the tool of your choice.

I agree with you - this update process is bad. Unfortunately, from the technical side I don't know of a better way. The problem is not solely with SmartGit but also by Mercurial's website and incompatible changes of their API.