Sadly, I don't think your point (c) is really that valid. With more
trains, people will NOT make less transfers - but instead they may
even make MORE transfers.
Please take note that not all the MRT lines ply the same route
in city, nor do they provide links to all the places that commuters
are going to. DTL2 is an example where you need to tap out at
Newton and then tap in again just to take one stop on NSL to
Orchard. (Although the fare system will be changed, the mode of
transfer will surely result in massive crowds at fare gates).
In fact, DTL3 will be worse but I shall not discuss here.
I have not even taken bus transfers into consideration yet.
Let's say you live at somewhere near NJC and are going to SIM. Are
you going to take a bus to Sixth Ave MRT, then take DTL for only 1
stop, and transfer to 74/151/154 again? Or are you going to just
take a direct 74/151/154? There are thousands of similar cases
especially for short-distance travellers. In fact, even some
long-distance travellers may also be wondering should they use
972-DTL-NSL or just a direct 972 to Orchard.
Regarding bus-train transfers, although DTL is generally better
than CCL, some stations still have bus stops so far away that deter
people from transferring to buses. Botanic Gardens is a perfect
example.
My answer is simple:
Even if I stay in Sixth Ave and I am travelling to SIM, I will
take bus. I had taken a closer look at Kings Albert Station, oops
it is so far away from the Macdonald. If I am travelling to Orchard
from BP, if I need to first take 972 to BP Station, I may still opt
for the more direct route 972 into Orchard. If I am a Sunset
resident and I am travelling to Bugis, I may opt for DTL. If I am
in CCK/BP and is travelling to NUS/one-north, I will opt for
DTL/CCL. If I am at NJC, I will still take bus to ACS and Little
India. However If I am at NJC, I will probably opt for DTL for
Rochor and beyond.
