Hmm, I guess you have to go a few steps back and then start again.
I think you try to do some effects that you are not enough skilled for. At least for now.
For example the blood and the damage effect. Don\'t get me wrong, it simply doesn\'t work for me. So my advice would be to try to make a clean dreadnought without to much blood or damage on it. You can attach the effects later if you want.
Well lets start with the metallics. When I started to do minis there was one technique I really got to get good effects on metallics. Well its not the fine high technique most people use here, but it will do the job for Beginners. Namely: DRYBRUSHING. Cause I think you really should get more feeling for paints, so lets start with the \"dry\" techinques. At least I got feeling for paints with that technique...
I would do it like this on your mini. Paint the autocannon, the claws and the the legs( Well the metallic parts not the armor plate) black again. Then you take some boltgun metal (if you just have this shiny metal you used try to add some black to it!) and drybrush it. Here\'s an article on the technique:
http://www.aircraftresourcecenter.com/tnt1/001-100/TnT087_Drybrushing_Bamford/TnT087.htm
Well its not for GW Minis but it explains the technique in nice pictures. Perhaps you can find some better article on it.
Afterwards you can post some picture here again or go to the WIP area in the forums.