After starting a local server I cannot see any minerals on the map at all. Is this expected? Or is there something that needs to be done to get minerals populated?

Once you link your github account/repository any time you update your repository those changes will get pulled into the screeps server. I set it up then started using grunt for pushing my changes because it was less steps that committing small changes constantly to git.

In my experience the changes from git only get pulled into the game when you make a commit. So, if you make a bunch of changes locally and push them into the game those scripts will not be overwritten periodically by the contents of your git repo. BUT if you commit to your git repo (I believe only master branch, but I have not checked others) your committed changes would overwrite your current scripts.

I think this works out rather well actually. Personally it allows me to work with scripts locally and then once I am happy with my changes push those changes into my repo. 

I also saw the recent announcement about work on the open source server and that it would not have the additional stuff they use currently, such as redis. I think it would be nice for those of us who are tech savy to first have the server released with that support and then work towards having it as an option that can be enabled/disabled.

I guess I sort of agree. It depends on level of effort. I am really looking forward to an open source server as well, but if that is going to a be a while off and it is not to hard to add additional rooms to the simulator, it would be nice to have while waiting for the server.

Could the Simulator please be expanded to more than just 1 room? For instance, have a 3x3 area of rooms for a total of 9 rooms.This would make the simulator 100000x better for testing.