No. The modpacks are near useless for single player. We have build our server using the resources of the modpack but with the much needed help of bukkit plugins. This modpack is only recommend for our server use only.
1. Players can connect just fine. 2. Yes I have tried the straight ip with the port, tried with masked ip through my domain (ex. mc.domain.com) 3. This server is hosted and I've had not trouble adding it before when it was a bukkit server.