Full details are in the CIC Regulators Handbook but simply any work done for the CIC can be done at market rates, Directors can be paid for work they undertake for the CIC.
It could be difficult to ensure it doesnt look like a conflict of interest. Obviously you need to ensure as Directors of the CIC you arent working for the betterment of others, but instead working for the CICs best interest. That leads to questions like why do you want to start the CIC, obviously in your case I can see the areas you want to expand into and perhaps the need for grant funding etc to achieve it. Id personally say as long as all might be regarded as reasonable and honest by the general public you'll be fine. Perhaps a short email to the Regulator for guidance would help, as will reading the guidance notes.
Contracts must be for market rates etc, one point to understand is your companies may be regarded as associated for HMRC purposes, a quick google of associated company hmrc should bring you up to speed.
Best of luck
Yes, basically you are loaning the money to the CIC and can take it back when appropriate. The CIC can also 'owe' you for hours worked getting set up etc which it can repay to you when prudent. IE....the board agree that you work for £15 an hour but there is no cashflow to pay at the start. This debt to you can accumulate until you do have cashflow to pay, or you can decide to waive the amount owed.