Personally, Indy not using his whip is like Star Wars with the Jedi not using their lightsabers...I understand about the new/unique weapon in ROTLA, but it's still his "signature" weapon/tool...honestly, I don't really even consider the end of KOTCS where he throws it to Mac as really "using" it...I think that whole sequence is horribly paced and shot, with Mac "falling" and Indy tossing him the whip, but to each his own...
Anyway, in the novel he uses it quite a bit...one part in the novel he uses it, and it's also in the comic, is when the warriors are chasing them down the stairs of the temple outside, before Ox takes out the skull to scare back the warriors...Indy supposedly uses it to take down a warrior or 2...wonder if that was also filmed and not shown....
I wonder, if there were an Indy 5, if he would even use it but once or twice, and even take out his gun...I mean, isn't SS the one who replaced the guns with radios in the speciall edition of ET....ah well...count me in with hoping for unseen footage when KOTCS comes out on DVD, and maybe for all 4 movies when they eventually come out on Blu-Ray.