I agree with others for the 1st and 3rd sentence.
The second sentence "I have worked here for two years." does not always mean "you still work there".
It would not be natural in its current form to emphasize you still work there and the sentence was only a made up one (not resulting from a real context), and that is why it does not sound natural to emphasize that continuity. It would not have been said for this purpose in a real life situation.
Actually, the Present perfect with the number of years is not used to emphasize the fact that "you you are still working there." (In that case, you would use perfect countinous.) But it is used to emphasize the experience, the action itself, may be the effect of that process in your life.
For instance, if you are not a sports fan and someday if you played unexpectedly better than your peers, somebody might get surprised and ask you "Wow, you play football very well. That was shocking. I didn't know that".
Considering your experience when you were at school team for 2 years, you might say "I have played football for 2 years." (It does not mean that you are still playing there. It means it has an effect on my life which you can still see. I have such an experience of 2 years.
I hope I was able to explain.