How to configure FlowWright multi-tenant sites exposed publicly to the internet?  

You can set the public DNS to any URL you want, you will have to change the URL within the FlowWright configuration settings to the new URL, and also the FlowWright multi-tenant URLs. Use ports 80 or 443 for https traffic.

Given we would have multiple tenants under one server, would we need to implement a DNS entry per tenant so that each URL is uniquely different?   What IIS changes (If any do we need)?  

You need 1 DNS entry, for example *.yourdomain.com. If you tend to use SSL, you will need a wild card certificate for *.yourdomain.com. You may also configure IIS to be *.yourdomain.com

What would you recommend if we had multiple servers with multiple tenants per server.  If we had a wildcard, would we need a different domain per server or?

You don’t need a domain per tenant, only the parent domain is required, so you can do something like this

*.fw.forwardadvantage.com

each tenant will have the following then

tenant1.fw.forwardadvantage.com

tenant2.fw.forwardadvantage.com

you only need to configure *.fw.forwardadvantage.com