I am an ex-police officer.
With regards to ur question:
1) Yes, there is a prospect in SPF as a JO, but u must be prepared
to work in investigation and get a degree to be promoted to SO. If
not, you will lose out to the degree holders JOs.
3) U can try apply after working a few yrs, think they will take
into account the number of years of service in the force. Many
sssgt/ssgt are taking the degree/diploma in justice studies.
My advice to u: if u wanna be a PO, stick to being a PO. Narcotics'
officers job is very different from PO. To maximise your prospect
in SPF, i would advise u to get a degree while studying part-time
and then work in investigation. Once u shine in investigation and
armed with a degree, prospects in SPF is good.