If all life on earth, including humans, goes extinct, is that it for earth life? or, would it be just another extinction phase, and new life will develop? Could there ever be a time on earth where there will be no life? (More or less, in the future)

As long as the conditions to sustain life  exist, the possibility of it remains.

Yes, there could be a time when all life becomes extinct. At some point in the distant future, it is likely.

Depends on how polluted we left it and what could survive it .

Humans are very well known to bugger up resources and leaving source of life in jeopardy. Extinction of human part of the process no need to lose sleep over it.