Where do you want to see it?

This completely contradicts with our Changes view which always shows one single, full file (with both sides; maybe just strips some equal lines). Nothing that can be implemented easily.

How do you trigger the squash merge in SmartGit? I'm asking because squash is no option in the merge command in SmartGit but rather an option in the commit following the merge command.

You can invoke the file compare from the commit dialog by double-clicking the file - there is a blue (i) icon explaining that. But if you want to enter the commit message before opening the commit dialog, you may use the "Commit Message" tool window (Window | Commit Message).

smartgit.toolbar.longClickPopupOnly=true

Should I remove the drop-down-click area optionally, so it only can be triggered by long click?

I've implemented that because it offers a quicker way to access certain commands/command variants. Except of OS X (which uses a native toolbar implementation) the dropdown menus are not easily triggerable by accident (small click area), but rather intended to be shown on long click.

(Don't know what you mean with "in the review)

For 17.1 the Changes-view in compact mode will remain read-only. The staging/unstaging requires large changes.

My problem with this keymapping is that you will need to use 2 hands. Using a one-key-combination for the most often used command (go to next change), seems to be better for me - at least for the file compare.

In the Log's Files view please select the toolbar button "View all files of the selected commit.".