How was that lame? Considering the charges they had him on, why isn't that a good reason to have him locked up? Especially considering his being locked up led to the single best sequence in the entire movie?
I'd rather they come up with a good reason for him to be out of commission rather than come up with a whole bunch of super-awesome stuff that he did in the meantime that I can't watch and will be relegated to spin-off novels and comics that won't be as satisfying as actually WATCHING HIM be badass.
See I disagree, to me it is the adventures that we don't see that makes the world and universe feel so much more alive. To have the Star Wars universe stagnate for 30 years just feels wrong.
I also feel that time can elapse and important stuff go down without you seeing it, the OT is full of these moments. Hell, TCW was practically fought almost exclusively off screen.
Also, if not comics or books then video games certainly can supply these "super awesome" things and be visual.