1.Nc3: white develops a piece to a natural square. There is no way he can be worse after this logical move; you shouldn't fear hidden "refutations". 1.Nc3 is sometimes used by strong players as a way to trick black into some trasposition to selected 1.e4 variations (in return black has some interesting extra options of course).
2.d4!? in your line must be 100% playable, but i doubt it's best. I'm not a scandinavian expert and you likely know it's tipical themes better than i do, but i think Nc3 is not the ideal extra move on a scandinavian setup. In the scandinavian Qa5 lines (2...exd4 3.Qxd4 Nc6 4.Qa4 here) black usually plays c6 to retreat the queen along the a5-d8 diagonal. In many lines instead Nc6?? is a losing blunder which allows white to trap the queen. By analogy i wonder if 4.Qa4 in this reversed line might prove risky due to white's extra move. Also in the Qd6 scandinavian i think c6 is usually played. So the question is whether the extra tempo allows white a completely different plan (in this case the variation might be very good and interesting) or not (in this second case having Nc3 in might be a burden rather than an help).
I am now practicing scandinavian qd6 because I am so horrified with 1...e5?????
The van geet seems to be a unusual opening (1.Nc3) but I couldn't find any way for black to punish white. If 1...c5, 2. e4 brings us to the grand prix. If 1...d5 2. d4 brings us to the Veresov. If 1...e5 2. e4 gives us standard vienna. But what about 1.Nc3 e5 2.d4!? which is a scandinavian reversed. Any ideas on the position? Feel free to tell me what you think of the position (if there are any refutations I am missing) and thank you for all your comments on my previous forum.