Could you please explain what makes the coloring in GitKraken more useful than in SmartGit or other Git clients?

Of course, when committing there usually is a current branch, but the branch can be set to a different commit or deleted later. The commit itself does not know anything about "its" creating branch.

The colored lines are just there to make reading the graph easier for you, especially if line are crossing. Should we all show in black-white?

Maybe you should consider to group your repositories?

What exactly should be supported - simply displaying an image left and the other right?

Do you think that a i18ned interface would make using SmartGit significantly easier (if yes, why it is not easy now)? If, for example, you would write about a Russian error message to the mailing list, would an average English or German user be able to help you?

You already can complete complete file names since ages using Ctrl+Space. What do you mean with "keywords in diff"?

Even now the displayed structure can become quite difficult for back and forth merged remote branches. We wanted to keep it as simple as possible. The auxiliary branch already is a concession to make working with other branches possible. I would prefer to not over-complicate the matter to keep the focus on the current branch.