Being new myself I almost don't want to post this. If anyone has better advise please speak up, lol.
First thing the steel cutting is not likely to happen on a model kit. Everywhere that I have been looking says that the model kits are only good for soft metals (aluminum, brass, and maybe copper). For steel you might want to invest in a professional machine.
And when it comes to Resolution I see that it is all dependent on the adjustments to your machine. If you don't have it dialed in correctly your machine will produce slightly off pieces.