Ambient's version hasn't been upped in ages, so 1.44 is correct


- creating an icon:
Open "information" from context-menu, either press "create icon" or drop a PNG/other icon onto the default shown there.

-screenbar:
Right click on the depth gadget in the up-right corner of the screen, in the menu you can now select sveral modules including memory

- underscore:
If you mean something like "file_name" that should work, if you want to actually underscore a letter that won't.