It should be clear that the Committee has the responsibility for the Charity not the OC or the ACO, and therefore as Treasurer, the bank should use his/her particulars. Under Charity Law, the Treasurer is a Trustee and therefore accountable and cannot then hide behind the coattails of uniformed personnel.
And signatories for cheques could be two of three Trustees (but NO staff), although I found that Banks will pass cheques with only one signature, but if you use online banking, you would tend to limit access - having only the Treasurer with access is logical but he/she should fully understand the legal implications.
I think you could do well to read and understand the guidance available from the Charity Commission, none of which is embodied in ACP10 or ACP11. There might be one or two surprises which even your Wing Chair wont tell you about.
If you look at Scotland where all ACO Charities have to be registered with OSCR, you will find Trustee details recorded, except for some Wings, but then the ACO is not good at interpreting rules.
Interesting that your Squadron has been operating for two years without a proper Civcom- who has been managing the money then?
And as for meetings it seems logical that the Civcom would meet on a parade night. In Summer where there is scope for outdoor activities room should be available,and assuming sufficient staffing, the OC would be available to attend, being on site. Sparing him/her time and of course as parenst are Civcom members it will save them time and travel. It is not as if Civcom meetings are last minute affairs.
And of course on a parade night it gives the Civcom chance to see the fruits of their fundraising efforts.
But as a Committee, it can chose to meet anytime any place, and if the business at hand does not involve the OC, then date and time does not necessitate convenience on that count - but essentially you work together for the benefit of your Cadets.
Teflon mentioned the Squadron Associations This has been imposed on what we had before - we have Associations to which parents are members by virtue of subscription; the Association elects a Committee to manage the affairs of the Association, and from that Committee, some or all will act as Trustees of the Charitable funds - but as Rumpole said, you should have at least three. But none of this includes staff, uniformed or otherwise, if ACP11 is to be believed.
This arrangement is self contained and supposedly independent and the ball is now in your court.