Taking the OP's account at face value, The CM has no grounds to keep the money, and social services won't be interested in the odd biscuit.
There are usually two sides to a story, so it would be best to take legal advice. You may get some legal help through your home insurance policy. The CM will certainly have full legal support through her insurer/professional organisation.
I wouldn't think you'd get far with Ofsted. They conduct balanced investigations, not 'trial by message board' and will take account of the CM's side and all circumstances alongside the details of your complaint. In all probability, they will ask you to follow the CM's written complaints procedure and await her response in the first instance.
They will consider facts such as whether you thought it important to raise any quality of care issues previously and, if you did, the CM's responses to your complaints. They will also note that you were happy enough with the care to leave him with the CM for however long it was throughout, and wanted her to see out the full four week notice period.
The incident with the bark is very typical of what small children get up to. I can't see Ofsted making a big thing of it. If that puts a child 'at risk' in any official sense then there can be few CMs or parents who'd escape trouble from Ofsted/social services at some time or another.
Similarly, Ofsted are generally happy for a child to be secured in a pushchair sometimes, so long as the CM is always within sight and/or hearing.