All those things are acceptable.
Telling me to "Contact you after the show" or "Call me next week" or "call John Smith in my office because he's the one you should talk to...
I am about to give the the best advice to free up a TON of your time and save those of us that work the shows and derive our living from sales of goods and services.
When you take my time for a show, follow up afterward, a meeting, a dinner... you're not doing me any favors and you're not being "nice."
You are costing me (or anybody else in the same scenario) time, money and effort that I could be putting into another prospect or customer.