Look on forum topic How to merge a single line of text and not the whole block? with regard to your second feature request because this feature exists already and is called Line Mode Merge. And of course it is possible to simply copy the selected text with Ctrl+C to clipboard and paste it anywhere else in same or other file with Ctrl+V. It does not matter if a single character, a word, a phrase, a line or a block starting anywhere in a file and ending anywhere in a file is selected on copying and pasting the selected text.

I'm not aware of any feature or option to select a line on left side and at the same time the corresponding line on right side of a two-way text compare for active line window nor is there a button or context menu command to automatically select corresponding line in right/left file of clicked line in left/right file for active line window if this view is visible at the moment. So for getting such a feature in a future version of UltraCompare Professional it is necessary that all UC users interested in such a feature request it by email to IDM support as explained on tech support page.