Hi
I am in the same position.My daughter is 16mths and is quite advanced, adventurous and extremely independent. And she has also just given up day time naps ! ahh! So in a fortnight she will be starting one day a week. I am feeling quite torn and guilty at this stage as to whether i have made the right decision?? but in the end i think she will really benefit from the social interaction and the endless opportunity for play! If after a month she shows signs of regressing in development or stress i will pull her out and in turn if she flourishes will up the days! I did a bit of research and they say as long as they are nurtured at home they should not have any problems. But eek i feel for you such a hard decision!
Also definitely great idea to pursue studies. I am doing part time study at uni and i love it!
Well all the best hope it works out for you.