Not sure what sort of issues, if any, will arise with someone else adding ideas. I think of it as a double edged sword, much like any other relationship. They may have ideas that I do not like and others that I think are phenomenal. Its going to have to be a compromise.
The first of these ideas is switching the game to an online one. I had seriously hoped to make it single player before I delved into the finer details of networking, but at least now I have support if needed.
And since my registered version of GM supports online multiplayer, I was pushed over the edge of the single player cliff into the online void below.
What have I got to lose though really? It can always end up single player should multiplayer not pan out. Might as well give it a shot. :D