Does anyone know how to center my newly created brushes with the path? When I increase the stroke it simply goes everywhere.
I would start by playing with the options of that particular brush:
To change the options for a brush, double-click the brush in the Brushes panel. Set the brush options and click OK. If the current document contains brushed paths that use the modified brush, a message appears. Click Apply To Strokes to change pre-existing strokes.