i can understand your annoyance with the hat- unfortunately things do get misplaced/put in someone else's bag/dropped at the park, its best just send child in second best items.
my main point to you though OP, is that if you are uncomfortable now, its unlikely to get better.
some of your worries may be genuine concerns to ofsted, however, its difficult to say without all the facts, if the assistants are ofsted registered and have all the relevant qualifications, they can be left for up to two hours. if she was upstairs sick, and left the assistants in charge, its not professional, but not necessarily wrong, if she was in earshot or eyesight, CM could argue that being on the premises was enough to adhere to the rules in this instance.
will there be anyone else with assistants when the Cm is on holiday? if you are certain assistants will be left alone, then you need to report this to ofsted immediately.
the play and sleeping arrangements- did you not talk about this before starting with CM? she isn't dOing anything wrong there, and if she is graded outstanding, then ofsted obviously think her play and sleeping set up is great. have you read her ofsted report? I appreciate this is your first experience of childcare so you may have not known all the ins and outs, but its so important to going and visit lots of settings, and do your research on them!
did you sign a contract? what does it say about notice period and returns of any deposits?