So, this is what I'm thinking. Is it clear? Any thoughts/suggestions?

Can someone inform me of the average grade recommended when using the 18-Piece Graduated Pier Set? Also, what are the heights of each part?

I'm just beginning in the HO hobby and my latest purchase (as of about 15 minutes ago) is the Emily, tender, and two cars set. I'm wondering how many additional cars is possible without making the train far too slow or risking damage to the engine.