How do you cut and paste part of a line of text that is separated by spaces. eg. two addresses on the same line. When I try to select part of one address, both addresses are highlighted for cutting.
This should not behave like you describe. There must be something special to your case: the addresses might be a part of a single field; or you have some curiosity OS settings; or some other unknown in the equation. You could provide a sample document so that others could try to reproduce and give better advise.
Regarding the mouse, Writer is character-oriented. You select a character at a time. You can double-click to select a whole word, triple-click for a sentence, and four-click for the paragraph.
The exception that comes to mind is if the characters are in a Field. You can go View / Show Field shadings (shortcut might be Ctrl-F8) and the field will show a background color. Or simply double-click the text, and if it’s a Field the Edit Field dialog will come up.
Unless perhaps you’re in Calc rather than Writer. (It’s a good idea to use Tags here to narrow down where exactly the problem is occurring.) Calc is cell-oriented, and in order to work with partial contents you will either have to go to the edit box above the sheet, or double-click directly on the cell.