There are snippets of this sort of info all over various ATC, ACF websites. I remember the Official Air Cadets website saying that a CWO in the CCF may only be present when there are at least 99 Cadets parading in the entire contingent. Other than thatm rank was at the discretion of the Contingent CO.
In short, a minimum of 2 AIs required. Preferably, one commissioned, one female, and the female can be the 3rd member of staff too. However, from what I've seen, its an ideal, not a minimum standard in many dets
Basically you need 51-75 cades to justify a Captain
JNCOS (ACF) (L/Cpl & Cpl) should have passed 2 Star (ACF) and JCIC (I think that's a requirement for completion of 2 Star anyway); an NCO Cadre would also be ideal. SNCOs (ACF) (Sgt & S/Sgt) should be at least 3 Star, but 4 Star training/ 4 Star is good too, as well as SCIC and Frimley Leadership Course (or equiv'). CWOs should have passed their 4 Star program.
I think Duke of Edinburgh's Award scheme comes into play in a couple of the Star Awards too.
I've also heard that in some Companies, promotion to L/Cpl is at the discretion of the Det Commander, while promotion to Cpl and above has to go through Company Commander, though it may differ where you're landed up.
Pass 1 star and a cadet may become L/cpl. 2 star and they may become Cpl, JCIC and 3 star- sergeant. SCIC and 4 star ad they may be C/sgt-RSM. Size of detachment affects promotions up to and including Cdt Sgt. Any ranks after that are deemed to be at company level and cadets of those ranks tend to travel roun all detahments in their company. That being said, a large enough detachment (30-40 cadets) may parade a colour sergeant.