First you have to define the problem you want to solve then attempt to present a solution. You appear to want to serve the ultimate in convenience and service to a passenger, to have the passenger to do less walking, less waiting, while still be "economically feasible". For who? For everyone? If we all had limo service but not dedicated, we agreed we can all share limos, all passenger vehicles would be taxis and a significant part of the workforce were limo/taxi drivers, but we would have less cars on the road. Can we afford this as a society or is it going to be just for the few that can, and the rest would walk?

Minibuses and minivans end up being less efficient than anything else. In countries where cabs are allowed to pick up 2-3 different passengers if they find someone down the road going in the same general direction, end up with passengers avoiding to get on someone else's cab due to the routing, time, and ending up with about the same cost. There are 7-9 passenger minivans, imagine all going to different places and imagine being in the back and having to get out. Even small buses on local satelite routes end up being very costly due to single door multiple stop routes. EVERYONE wants to be next to the door and not have to rub and push people to get out.

Trains, multicar trains with more than 45' between stops, are extremely efficient. Small local trains and metro/subway is much more costly pass/distance than trains. Fewer cars, exponential energy cost, tremendous infrastructure. Large buses beat small trains overall, in urban environments. (Raising a train on ramps over the roads costs 2-3 times more than having them on street level. Putting them undergroun on an already built city costs 2x more than raising them up. Trains take an enormous amount of energy to accelerate to cruising speed, little energy to maintain it, and another huge amount of energy to stop them again (mostly heat realeased, little generator energy recovered). To have them accelerate and stop as frequently as bus stops they become as costly as passenger cars.)

Cycling for able bodied passengers in a priority to cycling transport system beats everything. Just a video clip of Holland urban centers is proof of concept.

So what is the problem you are attempting to solve?