I thought it was a fun bit the first time he fired the bowcaster. We had never seen it before and it made sense in the context of the situation - Chewie being hurt and unable to hold it. The second time, we’ve already seen it, and Chewie was running around with it just moments before that.

I agree that there’s nothing wrong showing Han’s age, I just didn’t explain myself very well. It looks obvious that they tried to hide his age the way they shot it (and failed to do so), rather than just owning up to it.