I have two SGG Shafts with standard Handles, And a spare SSG with counter balance weight. Would like the oars to match the spare. Is it hard to remove the Handles and put counter balance handles in? if its too much hassle I will just add sliding counter balance weights...

you cut the rubber part of the handles off, you can go to sportco, and get replacements, just wet the handle and they will slide on

There is a difference between standard shaft handle and counter balance Shaft handles. The handles are weighted on Counter Balance shafts correct? Foam covers dont come into play here, as i understand it.