Don't throw in any raw shrimp or otherwise deliberately pollute your tank! You can cure rock in your tank, but ideally you're better off buying rock that is already cured, or curing it in another aquarium, with lights. Since you're only using 40 lbs in a big tank, it doesn't make that much difference. The ideal scenario would be cured rock, then you're still going to have a little cycle, but not a huge one. That's better; you won't be loading up your new tank with nitrate and phosphate from the cycle, and thus you can avoid a big algae bloom. Don't worry about "jumpstarting" the bacteria population, that's really kind of silly. There is bacteria present in every tank, on every piece of liverock, etc. already and it will colonize and die off depending on the bioload. Once your rock/sand is in and any residual ammonia is gone, you can start stocking the sand bed with microcritters; do this by buying livesand from Tim, inland aquatics, IPSF, or getting some good innoculated sand from someone with a very established sand bed.

Don't add any additives; there's plenty of stuff in salt mix. Good luck!

Two good books to read are "The coral reef aquarium" and "sand bed secrets" both by Ron Shimek.