Thinking that this team will be pushing for a playoff spot in its first couple years is very optimistic I think. I would bet they finish bottom 5 both years, but its better to pick 1st than 5th. Tanking is a good idea and a practically a necessary one in todays cap league.
I think that just tanking for a higher pick is a bad idea, especially given it doesn't guarantee anything (the Leafs were very lucky to stick at 1), and Vegas won't have any real prospect base anyway, which means that they'd still having a crap team with 1 or 2 youngsters rotting.
The best bet is to sell cap space to teams in the expansion draft. With a flat cap, teams like Chicago, San Jose, Pittsburgh, Washington, LA, St, Louis, New York, Boston, etc are going to be in tight to re-sign players who need to be re-signed and would probably pay to be rid of contracts like Kruger, Boedker/Dhillon, Eller, Greene/Brown, Klein, Belesky, etc... Also, teams who don't want you to take player X, Y or Z will pay up at least a mid-round pick to avoid it. i.e. Minnesota may give up a 2nd or 3rd to take Zucker over a guy like Brodin or Scandella, rather than trying to trade them for packages of less valuable players who are draft exempt.
Take those picks you get for taking on poor contracts, use McCrimmon to build up a strong farm over the first couple years. Even with some poor contracts, you can sign a couple FAs to deals and be decently competitive if Foley is willing to spend, which, all indications are that, yes, he is. When those contracts are out, you start to bring in the kids and hopefully everything works in their favour to start being a real good team in year 3-5.
I don't think they necessarily have to tank to build up a farm. It's more making smart use of all their assets, which having $73M in cap space going into the draft is a massive advantage. You pick up 5, 6, 7 extra picks in the first 3 rounds of the next 2 drafts, and it gives you a lot of options to add some talented youth.