Don't chase horsepower numbers. Especially as someone a bit green to this. All dynos are different, etc.
Enjoy the car, but don't shoot for a number. It's a silly exercise.
No it doesn't. You can swap DI injectors all day.
It's either the injector or the plug since you ruled out the coil. You're clearing the codes in diag mode each time, and it comes back right?
I decided I liked the Prismatic Universe, so we did the rears too.
Also threw an exhaust on it for street driving. I'm too old, and it's too loud with just the dump.
This is clear an issue, especially based on the video from @Spart however,
This has always been the rule for ever and ever, amen, for manual transmissions. I cannot imagine I've been in where I've not left an MT car in gear-- at least when exiting.