I have questions!
1. What is a "static"?
A group with a set roster of members who meet regularly to tackle specific content; basically a raid group. This is usually 8 people (2 tanks, 2 healers, 4 DPS) who work through the end-game raid content together. Sometimes people form statics for other things--like grinding out primals for birds. People who don't have a static can still PUG (pick-up group) the endgame content with different people week to week, but generally having a static will get you faster and more reliable clears.
2. What are "A10s" and "A9s"?
The first and second floors of the current end-game raid. In ARR, at level 50, the endgame raid was the Coil of Bahamut; there were three tiers of the raid with The Binding Coil of Bahamut landing in 2.0, The Second Coil of Bahamut in 2.2, and The Final Coil of Bahamut in 3.4. Each Tier had four or five encounters in it, called Turns, and are usually referred to from T1 (the first encounter in the first raid tier) to T13 (the last encounter in The Final Coil of Bahamut.) 2.3 also introduced a Savage (harder) version of The Second Coil, so the floors in Second Coil, T6-T9, also have Savage versions which are referred to as T6S-T9S.
With Heavensward, they made the endgame raid Alexander, and had two versions from the get-go. There's a normal version, which is sort of for everyone, and then a Savage version, which is meant to be the more challenging endgame raid. Each Tier (Father in 3.0, Son in 3.2, Creator in 3.4) has four floors, and the popular way to reference them is A1-A12. A1S, then, is the Savage version of A1, etc. The current endgame is A9S-A12S. The cutscenes and everything are the same between the two versions, but the encounters differ with the Savage version generally being more mechanically complex and hitting harder.
3. When I killed Titan the other day, I got my fourth crystal, despite having killed only two primals (Titan and Ifrit). What were the other two crystals and how did I get them?
Somebody who doesn't skip cutscenes can answer this.
4. How likely is it for Heavensward to be on sale on PSN during Black Friday? I'd like the collector's edition that is currently 60$CA on PSN.
I'd guess likely, but it's worth noting if the CE doesn't go on sale and the normal version does, you can just pay SE $20 to digitally upgrade your to the CE for the extra in-game items.