Surface layout looks a bit better. Your surfaces still contain a lot of control points. Which means the curves you have used to build your surfaces from are too complex. Clean up your curves first. Preferably keep them single span. Use CurvatureGraph to check the curvature. Line up curves with Match.
Start with simple surfaces, you can always increase the complexity or degree of your surfaces if you have trouble matching them. You can Rebuild, RebuildUV, ChangeDegree and if really needed insert point or knots.
I wouldn’t use MergeSrf. Try MatchSrf. You can select Multiple Matches.
About the surface layout. Make two separate surfaces for the top and the blend towards the side. So first create the top surface, then the side and then draw a blend in between.
I would not use RailRevolve or Revolve for the surface on the left side. This surface is too hard too match up like this. Instead trim of the corners of the top surface and use a two rail sweep or EdgeSrf.
Goodluck. Also look up information on surface continuity and patch layout.
http://help.autodesk.com/view/ALIAS/2016/ENU/?guid=GUID-A23E9E8C-6D6B-41AD-A0AB-3E98183FBC2E Should get you started.
Not sure if Rhino has a similar list of golden rules, if not they should make them.