The pre-destined thing is definitely not applicable to
anyone.
Not all deployments are done by CPC, FYI. Some units have
different formations in different camps and they have the power to
decide who goes to which unit. When that happens, please don't
blame CPC.
For me, proximity of camp to residence is not the most important
thing that a serviceman should consider. It's the level of
regimentation and the attitude of commanders that one should be
concerned when he is serving NS. No point living 3 minutes from
camp when you get treated like dirt.
Academic results do play a part. For example, having a diploma
in electrical engineering might increase your chances of being an
electrical technician (if you are not considered to be good enough
for command school, perhaps). Getting three or four A level
distinctions might increase your chances of becoming an ASA (Asst
Chief Clerk or project clerk), if you're not deemed to be combat
fit. Hence, it pays to study well.
Some postings are randomly generated by the computer as
well.
You so sure about the academic part? As a technician, majority
of my peers from poly all belongs to science, IT, business with
very few in the engineering courses so i highly doubt the accuracy
of that statement.