Well first train set is up an running and had a question about building some roads / streets

First I will let you know a bit about the layout I have.

Built a 4' x 8' table framed out with 2 x 4's .   on top I put a 1/4" piece of oak and on top of that I have a 1/2" sheet of 4 x 8 homosote screwed down and painted green

I have a few roads I want to put into place.  I looked around online and saw the main way was to use drywall compound first spread out as the roadway, sand when dry then paint with asphalt topcoat.    Is there any other method to accomplish making a road?   Reason I ask is..... I have the train completely setup and light poles in place along with a lot of other items glued down already so the last thing I would like to do is have to do a lot of sanding of drywall compound and making a mess that will be difficult to clean up. 

I know I should of thought of this before laying the track down and everything else but i am new to the hobby and did not give roads a thought until I had everything setup

First let me explain..... I completely new to HO Trains

Bought my son a Bachman Echo Express DCC setup.   Bout some extra track with a few that have switches for his layout.

Yesterday was first day running the train and I noticed that the front wheels of the locomotive occasionally come off of the track rails.   I looked at the screw holding them in place and it is as tight as it will go so there is no adjusting I assume.  

Today the train keeps coming off of the track at one of the curves that is actually a left turn switch.   It seems to stay on the track ok if it is taking the turnoff but if I have the switch in the main position to continue on the main track it seems to come off at that point every time.   I run the regular cars across that section by hand and they travel smooth and never derail (only the loco)  Am I missing something?   I noticed where the loco attaches to the coal tender there are 2 small circles for the pin to attach into.   Does it matter which one it uses?

By the way I am using the Bachman EZ track