Starcraft 2: What Protoss strategies should I learn?

My style:
1. I enjoy Protoss so don’t try to sell me on another race.
2. I tend to have a relatively low APM (mid-30s).
3. I’m better at macro than micro.

I think I should probably start with the standard 4 gate but I’m wondering this:
1. What specific opening I should learn first?
2. What strategies I might explore after that?
3. Which strategies are suited to 1v1, 2v2, 3v3 and 4v4?
4. What are some race specific strategies I can exploit when playing PvP, PvT and PvZ?
5. What can I do to improve my micro and APM?
6. How do you use the group hotkeys?
7. How can I exploit my strengths at macro and less my weakness at micro?
8. How should I practice? Custom games versus AI? Real live subject on Battle.net?

I’m not particularly hardcore or worried about doing well but I’ve just been watching a bunch of Husky’s videos and wanted to raise my (light) gaming to the next level.