Contrary to popular belief.... promotion is not exactly based on
paper.
Yes, scholars have an advantage because they have a certain path
up to LTC planned for them. But at every promotion, they still must
meet criteria (such as unit under their command must pass ATEC or
other equivalents), he must have proven himself that he can command
and handle things without messing up + pass IPPT. If fail IPPT,
unfit, regardless whether you got Ph.D. or what also no use,
strictly no promotion. Also, every year, regulars are assessed and
graded by their direct superior (their boss may not be a scholar
like them). They must show their results (pass ATEC, men under them
high IPPT pass rate, no negligence on admin/logistics/manpower,
exercise results performance...etc.). Their promotion to the next
grade/rank depends on this grading annually.
You first question - how to be promoted to Major and above?
Performance. Like mentioned, there's annual grading of individual
performance. For pilots their flying performance (safety record,
good control of aircraft, skills in flying/fighting are assesed).
They are also categorised to their skill levels. A higher rank
pilot might be categorised lower than a highly-skilful lower
rank.
In short - promotion is not guaranteed. There're criterias (which
is basic, such as passing IPPT), but it depends very much on
individual, even for scholars).
To stay in the force beyond 45, officers must attain at least LTC,
or they will retire with a Major (Retired) at that age. There're
even people who retire with CPT (Retired) - meaning they only
reached captain rank at 45. These are the sissy, weak, indecisive,
unfit officers....shameful.
Your 2nd question - The military is not just a career. It is a
disciplined force. You cannot quit as and when, or apply leave/late
for work as and when. These are dealt with severely with
punishment, warning letters, demotion or even detention barracks.
Expectation on behavior etc. is very high - especially since all
pilots are also officers. Flying military clocks less hours on
paper, but skills you learn are far beyond the commercial pilots.
Commercial flying is a totally different thing, where you can enjoy
nice hotels, food served to your cockpit, reading announcement to
your passengers.... commercial pilots take >10 years (typically
15 years or so) to reach captain. While in military, every pilot
flies their own aircraft...albeit with heavier responsbilities of
an officer/soldier. They don't just fly, they have to fight and
lead.
Your 3rd question - Pilots fly...of course. So do WSO (Fighters).
Half the time is ground preparation/briefing/tactics
discussion/preparing for exercise. They don't just randomly take
off as and when. Every flight is planned with a purpose, with
objectives - its called a mission. So half the time is mission
planning. While in the air, pilots fly the aircraft/shoot planes
down....WSOs operate sophisticated systems to drop/guide ground
weapons to hit targets on the ground accurately. They are also
secondary(backup) pilots. They practise dropping bombs/fire
missiles regularly at one of our southern islands. Due to lack of
space, they can't do fighter manoevres over Singapore skies, they
will crash into the hundreds of passenger planes coming in
everyday....these take place at South China Sea....and majority in
the USA where we keep a detachment of planes/staff permanently
there. Pilots/WSOs are rotated through there regularly....that's
the first place fighter/WSO training takes place too. So they
train/hone their skills in Singapore/USA and take part in
multinational exercises with other airforces to sharpen and
validate their tactics.
Fighter/WSO job in Singapore is quite exciting..because RSAF
operates one of the most advanced variants of F-16D and F-15SG. It
has very unique configurations, sensors, electronic warfare,
weapons suite....unique and more advanced than those used by
USAF....