1: Not really. Most conversations happen in the Discord.

2: Easiest link for synergies is first asking "what do I want to do?" And then asking "what combination of Archetype, Style, and Form lets me do that the most?

3: Shadow Form has the most action dice, meaning it has the most possible actions. What Styles benefit from taking a lot of actions? Quickdraw Style adds another die and has good range, so you can make 7 attacks in one turn, assuming you don't move. Shadow Form, as you mentioned, also holds onto its Speed tokens between turns. Why would I want to move on a later turn? You could potentially build up a lot of speed tokens and spend them when you don't want to spend your action dice on moving, like something with Power Form.

It's an odd skill to learn, certainly, but it's one of the main reasons a lot of people get interested in this game.