Publishing is distributing a game to others, I'm pretty sure that this is not allowed with the team editions. Your students can show their games but not give them away and you can not produce a distributable EXE file.

DLL files can not be created with Gamestudio at all, you need a C++ compiler like Visual C++. I think the free VC++ Express has the same restriction - you can produce DLL files but not distribute them.

Hope this helps. For being 100% sure you should wait until next week for Conitec to comment, or ask their support.