I too am managing in the lower leagues. I have completed one season with Stockport in the Skrill North and sitting mid table in the Skrill Premier in January. I have found that the 4-5-1 is a tough formation to perfect especially against your equals, which in those leagues is everyone.
In terms of your DM-MC-MC triangle I have found that using the right MC as an Advanced Playmaker (AP) and the left MC as a Box - Box Mid (BBM) and the DM as a DM Defend is best, but your full backs need to be full back support to offer the width that you AML and AMR don't provide when trying to keep the ball. The DM will drop back to help the two CB's. Somewhat similar to how Roberto Martinez has Everton playing.
In the attacking triangle, your best bet it to use the AML and AMR as wingers (W) attacking. And the striker as a Target Man (TM) Support. The TM will drop deeper to retrieve the ball from the midfield, spread it wide then get into the box for the cross, if it is cleared the AP will be sitting on the edge of the area waiting to pick up the loose ball and try again.
I hope this helps a little towards what you need