I think there is no max limite for classes, you can take as many as you wish.

First option :)

Hi! In the first exemple you are postponing an action because you need to talk to someone first. In the second exemple something hadn't happened until you had talked to someone, but it's in the past.

There is a value difference between competent and proficient: While both refer to knowing a skill, competency can refer to the bare minimum required for acceptability. Proficiency carries with it a level of mastery that is above the minimum. "Competent" lives in an either/or framework . One is either competent or incompetent. Proficiency continues: "I am gaining proficiency in reading". One can be competent without being spectacular, but continues to grow in his or her proficiency. Accomplished refers to having a successful track record of achievements.

Yes! I would just say "stop talking to them" ... and "they have" instead of "they've".

It's usually fast, they always answer my requests within 24h.

Hi Abhishek, In the first sentence, you're talking about a possibility, a warning, a hypothesis. "If you do that, it would be a mess". In this case, I'd actually say "If you would take more than..." The second sentence it's definitively a hypothesis about something you didn't do. "If you had done something, it would have been a mess." The third sentence is like a warning, you're telling someone about the consequences of an action. "If you do that, it will be a mess."