I am sure there is a proper way for this stuff to go on. I usually put down a primer coat for any kind of paint....usually grey....but with Metalizer....do you have to use a certain primer in order to acheive a certain color? I know the Allclad stuff you are supposed to put it over gloss black, just wondering if the Metalizer is the same....or will any primer do?

Also is it a must to use the Metalizer Sealer? Or will normal Laquer gloss and dull coats do?

I´ve used the MM Metalazer in one Mustang P51 D (Tamiya). First I apply a base coat (primer) of MM camouflage grey, not to obtain a certain colour but to make a surface where the metalizer can stick well. I don´t know the result of using Laquer Gloss, I used Metalizer Sealer and the result was very good.

I believe Model Master recommends not using a primer but applying it to bare plastic that has been sanded very smooth. metalizer is laquer based, a "hotter" paint than regular enamel and bites the plastic quite well. The recommendation to use an airbrush is for that reason to a great degree. Brushing it on plastic may cause crazing. Metalizer also lays down a very thin layer of paint anda primer coat would defeat the effect of smooth, bare metal.
I'd suggest using an initial light coat of metallizer as your primer. Buff it out, then add your final coat. You might use a couple different shades of metalizer and get some variety by buffing to different sheens. :-)

This is true, never primer, All surface imperfections are magnified 100x once the metalizer is dry, Use the sealer, then decal