The show is no place to discover that your program gets lost on power up. Planning is everything. Some of you might be considering a robot with multiple moving axes. We strongly recommend that you get one axis with one motor working perfectly before going on to the next. That way if you fall behind, you will still have a working machine for the show.
Reliability is everything.
For a rehearsal, run your machine 10 times, disconnect and reconnect the battery, then run it five more times. If everything goes smoothly, you have a reasonable chance of success at the show. Liquids are problematic. They are hard to transport hard to hold without leaks and hard to replenish. Also, see the design rules for the maximum amount of liquid allowed.