I can't get Kerrigan Power 70.
This must be done in one campaign. Restart on Normal or Casual and get every Kerrigan level to unlock.
There is a workaround if you have a game saved before Conviction. Load this save and use the in-campaign archives (not the Master archives) to get all Kerrigan levels. You should have 59 before starting Conviction, which gives you 11 more (9 for mission, 2 for bonus objectives).
My Kerrigan "total use" (ex: Leaping Death) achievements are stuck/bugged.
They're either bugged or badly explained. Although Apocalypse Now, Release the Kraken & Drop Pods state outright they must be done in a single mission, the same is true for: Leaping Death, Smoking Corpses, Get a Grip, Surprise and So Many Banelings.
The "stuck" counter you see is your highest total in a single mission. If you surpass it within a single mission, you will see the total climb.
These are easiest to unlock by soloing with Kerrigan on The Reckoning, Casual or Normal. Don't forget to defend the Hyperion.
My achievements don't give me the animated achievement banner, even if they're unlocked afterwards.
This is a bug caused by the option "set status to busy when playing." Go to Options > Social and restore to defaults. Then customize your preferences but leave "set status to busy" unchecked.
Are there any Feats of Strength in the Swarm campaign?
None have been found so far:
Why isn't there a Brutal Completionist achievement?
Because it would be redundant with the Brutal:20 achievement. There are only 20 missions in Heart of the Swarm plus 7 evolution missions.
In Liberty, the Completionist achievement was meaningful because there were paths that chose one of two missions (Shatter the Sky vs Belly of the Beast) and many missions can be skipped altogether.
This is why Brutal: 20 gave a portrait in Heart of the Swarm but Brutal: 25 did not give a portrait in Wings of Liberty.
What are Mastery achievements?
There are 3 achievements/mission in Libery, 4/mission in Swarm. Mastery achievements are the 4th.
1. Complete the mission.
2. Altered objective on Normal difficulty. (Ex: Don't lose a structure on Zero Hour.)
3. Altered objective on Hard difficulty. (Ex: Destroy 4 hatcheries on Zero Hour.)
1. Complete the mission.
2. Altered objective on any difficulty. (Ex: Destroy 35 sentry bots on Lab Rat.)
3. Altered objective on Normal difficulty. (Ex: Complete Lab Rat in under 10 minutes.)
4. Altered objective on Hard difficulty. (Ex: Destroy three factories on Lab Rat in under 10 minutes.)
Only the first three apply to planet-wide meta achievements or appear on the mission splash screen. The fourth appears in a separate list called "Mastery" in the Swarm Achievements menu, with its own Meta achievement.
My guess is this makes the "main" achievements casual friendly, and offers more of them for a shorter campaign, while hardcore players still have difficult tasks, often harder than just completing a mission on Brutal.
It offers a clear distinction between "just for fun" achievements and those that are really difficult.
I do wish they'd add the related Mastery achievement to the Mission splash screen so you could aim for them without consulting a list or menu.
Are there really people complaining about the story?
Yes, though it brings new meaning to "First World Problems." While it was no RISE OF ENDYMION, I enjoyed it.