I'd play Greig at 4th line centre, it presents a very balanced team at centre. And prevents them from putting a clear top 9 winger like Perron or Amadio (who plays well with Pinto) on the 4th line. Greig can move up if say Brady gets in a fight and is in the box. He'll also get ice time on the PK and PP2. Kind of sucks for him, but good for the team's depth.
Going forward, I'd keep this lineup, and if we're against a tough team, go 11-7 with Gilbert in, and Gaudette out. Adding Zetterlund means we don't need Gaudette on PP2. Highmore is more needed in the lineup, as he's a regular on the PK.