I haven't been on the monorail for years and I'm having a slight problem with what I see. Have they removed a section of seat or was the camera lens distorting the size of the cabin? Also, altering the entry level will never happen for two reasons, one is that the trains were designed in such a way that the door would hit the platform if it were even with the floor and second, they have a quick, effective ramp system that has been working for 50 years now there is no need for it. It allows all the access that is required.
I'm not sure what higher capacity or numbers of trains would accomplish. The more that get to the parks at once the longer the lines to get in will be. For years it worked out fine that the frequency and quantity of drop offs enabled people to go through the turnstiles before the next train arrives. So it's a line waiting for the monorail or a line waiting to get in the park. There is just so much toothpaste that can be pushed out the end of the tube.