Menu - Auto start event, use "Input Processing" or something along those lines to detect a keystroke and use a fork command to show a certain image. Really simple, just tedious.
Bars - Kinda tough math. Cross multiplication of fractions.
N is the percentage left out of 100. X is the length of the bar used. For example, if the "hunger" bar meets half-way (%50) N becomes 50, multiply N by the 10 (cross multiply) then divide that number by 100 to equal 5, the length of the bar.
Another example, just for added confusion, if the "hunger" bar meets one third (%33) N becomes 33, multiply N by the 10 (cross multiply) then divide that number by 100 to equal 3.3, BUT, RM2K3 doesn't support decimals. Don't worry though, it automatically raises to the higher (if 5 or above) number. EG. 3.3 = 3, 4.6 = 5.