Finna can be used as substitution for 'going to'

'Im finna serve tiramisu for dessert at my housewarming party'

'Im finna do hot yoga with Becky at noon today'

'Im finna buy Anti on Itunes'

I used to. A tragic time.

i say "boutta" lol

I'm finna get a grindr if my man don't pull through.

Yes



http://youtu.be/hQUFkzpKq80

Nope

What does it mean?

Yes

whatcha finna dooz about it if I dooz bruh, jah feel

no

I don't think I hear it a lot

Not regularly but I do say it jokingly or to place emphasis on something when I'm with friends.
"I just filed my taxes! Bitch I'm finna blow this paycheck from last week [exaggerated cackle]"
to be exact lol
gonna/going to

Yes

'Fixin to'>>>>>>>>>'finna'

I don't recall myself actually using it tbh.

No

No, I speak English.

I've used it jokingly a few times but it sounds so awkward to me

Educated am I, do not say.

Yes, it depends on my mood though.