Yes you can use a Lansky or Sharpmaker in conjunction with a mouse pad.

Primary and secondary edges are best understood as follows-

1/ You get your scrapyard knife which comes with a very obtuse edge geometry. Using the Lansky figures which give an angle measurement based on a single side of the edge - not based on both sides of the edge like the Spyderco Sharpmaker - the edge is probably at 30 degrees....which would be 60 degrees if you go off the Sharpamker's method of showing the angles of the rods when fitted to the given slots...saying it simple...there is two rods on the sharpmaker...so both angles or sides of the edge are included in their standard 30 degrees and 40 degrees slots for the sharpening triangle stones....on a Lansky you use only one stone and rotate the knife....so you have only the angle of one side on the Lansky.

2. The primary edge is the one you sharpen first...it becomes the primary bevel. You start with either 20 degree angle on the Lansky or 40 degree slots on the Sharpmaker. This gives you a standard single bevel edge.

3. To reduce the cutting surface of the edge and assist in slicing...you can add a shallower second bevel or secondary bevel at 15 degrees on the Lansky or 30 degrees on the Sharpmaker....THIS TRIMS THE SIDES OF THE PRIMARY BEVEL....it does not reach the apex of the edge....if an apple seed shaped edge created by a Convex technique is the best shape to an edge...a primary and secondary bevel using flat grind angles is the next best thing...this gives a V shaped grind which has the top bits of the V intersected by a shallower secondary bevel. Hope this helps.