clutch maybe dragging a bit which would cause the hard shifting.
while the owners manual does list the 20w-50 for high temp areas, the 50wt limits cooling flow.
And I don't see an improvement to go to the high wt. oil. Also could be causing the clutch drag.
Back by the neutral wire coming out of the case, are two marks that show the limits of the clutch throwout lever.
Hold the lever up with you hand to take the play out and compare the lever with the marks.
oil leaks are difficult, the dam stuff goes everywhere.
Plug the puke line, clean the engine, take a short ride and check.
It can even come from the oil fil cap up front or the speedo cable on top of the case.
There's a couple of threads at the top of the RSD you should read thru.
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1344399573http://suzukisavage.com/cgi-bin/YaBB.pl?num=1366651397