Like i answer only if i agree with the answer or find it a strong point of argue ( not necesary that the person is agreeing with me ) but i dont like random answers sometimes some answers are completely crap and i dont like it .

As an appreciation for participation.

It depends on how generous I'm feeling.

I generally heart everyone unless they’re a major a-hole.

Yes - to acknowledge I read it

Not all only good replies

As a rule I know who will reply and who will heart
who will turn into a total jerk ,,some people can't help themselves

I try to acknowledge them with a like, unless they’re being a dick.