I recently purchased an SY Mikado 2-8-2 (HO) with DCC On-Board and have a couple of questions:

1)  There is nothing retaining the wheelset in the reag bogie of the locomotive, so it just falls out when you lift it.  Is it supposed to be this way?

2)  Instructions for programming the decoder are sparse.  Would the instructions on the Bachmann web site for the EZ Command 2 function decoder apply to the OEM decoder?

3)  If I replace the OEM decoder with a sound decoder with an 8-pin plug, are any wiring changes necessary?  Would it be necessary to add resistors for the head and tender LED lights?

Thank you for any assistance you can provide.