2... Nf6?! in the Sicilian

I'm playing a game right now with the Nimzo-Rubinstein variation of the Sicilian. I first discovered this by accident, but thought I'd give it a shot online. I haven't seen a whole lot of theory on this, but it looks pretty viable although somewhat unorthodox. It looks similar to Alekhine's Defense - after 1. e4 c5 2. Nf3, Black plays 2... Nf6 provoking e5 and the Black knight moving to d5.

Does anyone have any experience with this opening, or any thoughts?

Here's what I've played so far - I'm in a strong winning position due to a blunder by white on his last move, but I think it played out fairly well regardless of that. It certainly has been interesting and exciting!

(Since the game is in progress - please no comments for future moves)

How are those lines typically played out?

I figure maybe something like this for 4. NC3 would work?

The line with c4/d3 shows only one game in my database and black won it. It doesn't look very good.