1) If somebody has a press conference and wants to thank the first coach in his life what does he say?

a) He has helped me a lot
b) He helped me a lot

Since it is a general thought it leads me to think that option A is more correct. In option B the person is probably imagining a time frame in the past

2) If a player changes his agent what does he say to him?

a) player: You've made me a good player
b) You made me a good player

Again I think it's A because the player is good right now. If the player WAS good then I would say that option B is better

3) If somebody becomes a millionaire and then loses his wealth how is it better to say

a) I became a millionaire but I lost my wealth
b) I became a millionaire but I've lost my wealth

From a grammatical stand point option B sounds correct but for some reason I think that once someone starts to talk in the past simple, he has to continue even though the action might have a present relevance

So guys, I basically want to know if you think if I'm correct or not. I would prefer if a native speaker answers my question.

Thank you in advance Emotion: smile
1 The more recent the association with the coach, the more a) is correct.

2 Your logic is correct

3 This really depends on the point of view. I prefer b) because I want to think that the situation is not over and done with.

By the way, welcome to the Forums.
Thank you Emotion: smile And can I ask you another question ?

If someone has a girlfriend, breaks up with her, goes out with a friend one day and sees the girl, what does he say?

a) She was my girlfriend. I've kissed her before
b) She was my girlfriend. I kissed her before

What do you think? I think that they are both correct depending on the context. If somebody says option A I would assume that it's a general experience. If somebody says option B I would assume it has the same meaning as "used to".