G'day Anji,
2) I have the same 49 tooth on the back of mine (18 front), it is apparently standard for a side car set up (reference bacon book).
To be honest I have not had the pleasure of riding my bike yet, soon, so can not say if it will be reving too high for normal riding, if it is I will replace with a 42 tooth item from draganfly.
Have had the pleasure of riding a couple of Captain Orabanda's, with 18/42, they were pretty sweet.
Suck it and see I say.