About the skating: I think he is more of a Marchessault type skater (north/south). Doesn't mean he's not a good lateral skater, it's just not as elite as his speed.
I'm very happy with the selection. He will bring another weapon to the PP (probably 2nd unit at first). Obviously his strengths are hockey IQ, skill, vision, passing, and a good shot. Likely Rau will head back to Springfield after the game tonight. Some may wonder how he slid to the Cats in waivers. After Nov 1st, waivers selection switches from previous season record to the teams current record. Cats lousy play gave them a shot that they probably would not have had if the Leafs unloaded him prior to that date.
The big question is will Nick retain 3C. If Nick is going to play the wing, it's possible he may play the off wing as he seems more comfortable cycling up the left boards just as Jagr is more comfortable cycling up the right boards. In fact adding Nick to the 1st line just might rejuvenate both Barkov and Jagr. Have to wait and see what the braintrust comes up with.