Multipool or?

Hi guys.

I'm about to build my first rig and awaiting some parts that will hopefully arrive tomorrow.

I need to understand and learn how to identify what to mine and when (which is a big subject I know).

I'm curious about Multipool but OMG there is sooooo much to absorb and read, my head bleeds.

Here is my setup which might not matter for this discussion but still:

4x RX 570 Sappaire Nitro+ (I will get to a total 12 in a month).
Biostar TB250-BTC Pro 12PCIe
4GB Ram

Questions:

A: Multipool? As I understand, it mines what’s profitable, but is it a good place to start for a beginner?
B: I was reading about Dual mining. If so, if Multipool still a good option.
C: My interest is long-term not short and I want to keep building. Electricity is NOT AN ISSUE as the office I rent give me unlimited electricity.
D: Coins of interest, ETH, ZED, BTG when it comes out and if it kicks. What other coins should I keep my eye on?

Hope someone can help me make sense on this or guide me to a better solution.

Thank you.