Is there a way to select text in iTerm OSX using keyboard?
Yes! In iTerm2, do this:
As soon as you press tab or shift-tab, it is copied to the clipboard. You can press option-Enter to immediately paste the selection and close the find bar at once.
Alternatively, the autocorrect feature reduces the need for copy-paste. Just type the start of some text that is either on the screen or you have copy-pasted recently and press cmd-;. A popup window appears and you can choose from there. Autocorrect works best for a single word, though.