Hello and welcome!
The idea of multiplayer has already been said, but you have to wait for it (nobody knows how long it will take )

Stretching the game is going to happen. Remember - Factorio is in alpha stage! Alot of stuff will get added, we jsut have to be patient

I have sort of solution for the performace, with the help of actual "factory" buildings. Will write it down into detail right after i get some sleep.

And how about trains? Those are already in-game (but not hauling stuff right now)

I can imagine mining deposits far away, while making autoamted trains to go when full to the central base with goods/raw materials.

My vision of creative mode is having every item unlimited in my inventory. That way when I click on a particular item, I can drop it everywhere i want. In this mode you can build factories in no time without thinking what to research or craft first, pure building. (maybe turning off creepers would h...

IMHO mining and building times are going to be set (and actually some ARE set) to somehow balance the factories. By getting everything awfuly fast, you are going to lose one of the fun aspects in the game - balancing

Spin - yes, but it just blocks your wheels, so it is NOT a faster way to stop a car than normal brake :) Hand brake is also called "parking brake" - hence the name tells, it is best suited for keeping the car (or locomotive) parked. Pressing the opposite direction key didn't help you to st...