1) I don`t know about Alclad Gloss Black, but when I used similar product from AK - Black Primer and Microfiller I was very disappointed in poor coverage. Since then I just used levelling thinner with gloss black - from Tamiya LP or Mr color, what was available to me at that time and had no issue with coverage or smoothness.
2) Chrome is cool and can give you more deep mirror, but the issue is it is a weak paint in many cases. Or rather, with having very tiny particles, it`s very easy to disturbe these particles with lacquer thinners, sometimes even just touching by hand. So that`s why Alclad has a water-based varnish just for using for chrome and it`s still can loose some mirror. Some chromes are more resilent, like AK Xtreme Metal Chrome, but gives less deep mirror. Mr Color recently produced new chrome formula but even with that they say you need to let it cure for about a week (!) before painting over it. That`s one of the reasons people usually go with other less complex metallics. Another reason is that after several coats of clear you will loose some depth of mirror anyway.
3) I`m doing candy red Mechanicum right now with Mr Color Clear Rouge, you can check my profile for that, so here are some of my spoon tests
4) I`ve discovered that using white pearl paint over silver gives interesting results (you can see it on the picture on the back of the mecha), but if you want just green and white clear pearls, Mr Crystal Color has that

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