As far as forwards are concerned, the only guy avail as a college UFA who has a chance of being a top-6 guy is Taro Hirose.
Hirose is a typical NCAA undrafted star - a late bloomer and very undersized. If his skating is up to par, he could be a nice skill guy for someone. He's a ridiculously good playmaker with high hockey IQ. Size and speed are the concerns here.
Otherwise, Veronneau is Alex Formenton without the offensive upside, but his speed can play well in the bottom-6. Could turn into a nice two-way PK guy who puts up 6-8 goals a year. He is not a scorer - won't ever be at the NHL level.
Sturm is for sure going to be an NHLer, on someone's 4th line. His hands are not NHL level, but he's a defensive bulldog. Some coach is going to love him on his shutdown line making ELC money. Kid is relentless defensively.
Defelsively, there's Jimmy Schuldt, a left-shot defenceman who is easily the best of the defensive class (and quite frankly, the only worthy defenceman of note). Kid has a rifle of a shot and is improving defensively. Best case scenario is he's a 2nd pairing guy who can be the point man on your 2nd PP unit. He has a high floor, he looks like an NHLer for sure. He's already been offered multiple NHL contracts and turned them down.
Best goalie is Matt Robson, who is one of those goalies who has the skill to be a starting goalie anywhere, but lacks consistency. Will probably be an NHL backup or an AHL/European starter.