@Pyromaniacwolf So my main concern will be that everyone stays on more or less equal footing. To this end, I'm thinking of having everyone list their strengths and weaknesses. The way I was going to do it was have them list their core subjects in three categories, strong, average and weak. You can have any in average, but for every one you put in strong, one has to go in weak.
To actually answer your question: as long as the dark spells he knows are level appropriate, I don't mind the nature of them. I think it's heavily implied that Draco knew spells because of the darker connections his family had, even in earlier years. So, if we're starting first year, I don't want to see Sectum Sempra.
We could even revive my Dark Arts society, as a side plot. Could be fun, if more characters have the interest.
@Sergei Romanov Yeah, that sounds about right, if no one has any objections.