1. The duty cycle potentiometer should be labelled "Pot" or "Potentiometer". "Pot.meter" is not a normal abbreviation and could be confusing.
2. Your potentiometer doesn't need to be a 2W type. A standard potentiometer rated for 1/2W or even less is fine. By convention you only indicate important and unusual information on the schematic; even though you may currently intend to use a 2W potentiometer, the circuit doesn't require it, so you shouldn't show it on the schematic.
3. Your wire colours and thicknesses are right.
4. The MOSFET only has three pins. The pin at the right, which you have labelled "ns", is internally connected to the source. If you've created this schematic with a schematic editor, you may need to use a different symbol for the MOSFET. Also the MOSFET symbol should include the source-drain diode, which is internal to the MOSFET and is connected with its anode to the source and its cathode to the drain.
5. The two capacitors that you have marked "MPX X2 AC 275V" don't need those characteristics. X2 AC-rated capacitors are intended for mains filtering and are much larger and more expensive than common types such as ceramic. Here are three capacitors that are cheap, small, and suitable for those circuit positions.
http://www.digikey.com/product-detail/en/C420C104K5R5TA7200/399-4491-1-ND/818348 axial leads USD 0.23
http://www.digikey.com/product-detail/en/FK28X7R1H104K/445-5258-ND/2256738 radial widely spaced leads USD 0.29
http://www.digikey.com/product-detail/en/C320C104K5R5TA/399-4264-ND/818040 radial closely spaced leads USD 0.32
They are all 0.1 uF, 50V, 10% with X7R dielectric which means they are moderately stable and reliable with temperature and voltage variations.
That Chinese PWM looks pretty similar to your design.
The regulator is there so you can run it from a wider input voltage range. 12V is a good voltage for the main rail of this circuit because it provides plenty of gate voltage for the MOSFET, so it will saturate and have an extremely low drain-source resistance when ON, and it's comfortably lower than the 555's maximum supply voltage of 15V.
A standard 78xx regulator needs about 2.5V of voltage across it to regulate properly (this voltage is called the regulator's "dropout voltage"). So in order to get 12V out of the regulator, you need at least 14.5V at the power supply input, not 12V as claimed. The circuit will still work with only 12V on the power supply input connector, but the main positive rail will only be about 9.5V. Allowing for another 1.5V drop in the 555's output stage, that leaves 8V for the MOSFET gate-source voltage. That's enough to get most MOSFETs at least close to fully saturated; for a logic level gate MOSFET it's plenty.
On that Chinese module you can clearly see the heavy current paths on the underside, since they have been tinned with a thick coating of solder (and hopefully, some heavy copper wire underneath the solder).
