It would be nice if you have a CANCEL button on the Properties toolbar just beside the Properties button.
Good idea, thanks. We will add such feature in next build. Also, currently, you may use the double-tap gesture to finish the creation of annotations like polygon, polyline, cloudy, perimeter, area, etc.
2. I have a markup selected. How can I quickly delete it? I know that I can get the right-click-menu and select the Delete command from there. I would say I it inconvenient and slow. It looks like the whole concept of the editor should be reviewed to make touchscreens as effective keyboard shortcuts like Esc, DEL, Ctrl+C, Ctrl+V, etc.
You may create you own toolbar and add into it an corresponding items. You may do it by "Customize Toolbars" feature (from Menu/View/Toomars/Customize_Toolbars). It will display special dialog for customizing toolbars and menus. On "Toolbars" tab yo may create you own toolbar that will be empty initially. Then you will be able to add any existing command to this toolbar by D&D feature from "Commands" tab. For example I just created my own simple toolbar by this way and docked it on the right of Properties bar (sorry, but Properties cannot be customized, only your own toolbar or any other standard toolbar/menu):
One problem is - the customizing of toolbars by touchscreen is some inconvenient - sometimes its too difficult to put new item on toolbar in necessary position. We will try to fix such issues in next build. Currently you may customize toolbars by mouse on desktop machine for example, then export all settings by Menu/Edit/ExportAllSett feature and then import it on any touchscreen-device. Or, if its possible, plug-in the mouse device to you touchscreen machine just for comfortable toolbar customizing.
3. I select a stamp and want to resize it, and I can't do it with touchscreen. It is possible with mouse because I can see that my mouse cursor turns to double arrow, then I click and drag the corner point. Such functionality is not working with touches.
4. I select a polygon and want to drag its vertexes. It is not realistic because of the previous issue.
We will fix it in the near future.