Regarding shift click, it is a little bit longwinded process but you can do it this way:
1, open your inventory and GTN windows
2, hit ENTER to start typing into chat window
3, shift+left click the desired item in your inventory and the name link will be pasted into the chat entry
4, use arrow keys + shift to highlight part or all of the item name in the chat entry (or just use your mouse but do not copy brackets)
5, use ctrl+x and ctrl+v to cut/paste the text from chat entry into GTN search window
Only thing to look out for is NOT to press ENTER key while the item name is in the chat entry as you will submit it into the chat...
Though this should really work directly when you have GTN window open on your screen you can somewhat work around it