14 stops is a lot. From personal experience, I think that 5 or maybe 6 stops is the absolute maximum per line. Each stop adds extra loading/acceleration time, which means that passengers at other stops have to wait longer.
Also, while 4 buses per line is not too much, I try to maintain lines with fewer buses. Adding more vehicles stops helping the passenger load after some point, because they add to the street traffic and clog up the roads, leading to long stalls and increasing turnaround times.
In any case, I found (and many other players seem to suggest the same on these forums) that the best way to plan your layout is this. Have a metro line between two heavy-traffic areas (railway stations, airports, department stores, other landmarks), then start adding bus lines to bring passengers from a few surrounding blocks to the metro stops. If your metro stops are in quaint areas of town (e.g. next to the airport in Berlin), the buses will not get caught up in traffic and will be very profitable. Another good thing about metros is that you can add quite a few to a line, and they have large capacities, so you will almost never run into problems with not being able to pick up all the passengers in a stop.
Also, if you find a possible route that goes mainly through wide avenues with a green zone in the middle, you can build tram tracks there, avoiding traffic as well. However, make sure that your trams don't stall at that one narrow street with 150% traffic
Finally, if you have one or two out of 10-20 stops with a hundred passengers, that is not a terrible sign. But if most of your stops are like that, it's not good.