That’s one way. You could change the duration of “staccato” in Play->Playback options but I don’t know which is the least intrusive to how you’re working as it would affect everybody. If its only a note or two, I’d be tempted to leave the notation conventional and adjust the duration per note in the play tab.
On the other issue, you might check at the top of your expression map and see if velocity is used as part of your dynamics.