Either all heli pilots are ex forces,
Yup, pretty much! Or rather, the ones with 1,000s hours are! Many of the large operators were very short-sighted in their succession planning so, whilst there is a reasonable amount of work for twin-rated, IFR, 1000 hour pilots, there is a shortage of these experienced chaps. Many operators probably assumed that they would be able to recruit from ex-services without realizing that the RAF/Army/Navy were not recruiting or training so many pilots.
The other issue is the insurance requirements of many operators which may stipulate pilots to have, say at least, 500 hours for particular work.
The instructor probably is the best route unless you can afford and instrument rating and then the off-shore chaps MAY take you on as a co-pilot.
Sponsorship does not exist to all intents and purposes.
A Turbine (Jet Ranger) rating may be more useful than R44 but that will depend on any operators for whom you wish to work.
Cheers
Whirls