1) make sure that all router bits can be used on Every Dremel(supported) to the router-bit's maximum designed depth(deepest penetration and not less) without compromising how far you inster the bit in to the collet(saftey). 

 2)the depth guage is nearly useless as is because it doesnt reference from any point on a router bit.  What is needed is a reference point that is zeroed at the tip of the routerbit not at the routers full extention (this is because the bit wont reach the base of the router at full extention and its hard to measure how far the tip of the router-bit is from the base.  I recomend having the guage held in place by an adjusting screw on the top(plunging platform). 

3) Most important fix is to make sure the depth stops stay in position while the machine is in use(including in use on material).  The plastic markers have a horrible tendancy to rotate up and down eliminating the reference points that were just set(this means you cant go back and forth from one depth to the other).  (just use a set screw to secure them in location.)

It would also be nice if the distance face were able to be put as close as possible to the bit without being cut.

B.S.Mechanical/Aeronautical engineering graduate. Job hunting