None of your examples follow what I would understand as using tags. Here's how I would express your first two sentences, including tags in red:
Jack: He should have taken the medicine before the meal, shouldn't he? Jill: Yes, he should. Mini: No, he shouldn't.
Jack: He wouldn't have done that if I had stopped him, would he? Jill: Yes he would. Mini: No, he wouldn't.
Note that a positive statement [he should] is followed by a negative tag [shouldn't he?] and vice versa.
Also, do not leave a space before a punctuation mark. The space comes after a punctuation mark.
"I doubt some of them are wrong" is not correct. It should be "I think some of them are wrong", or "I think some of them may be wrong".
It's "Please correct me if any of the following sentences are wrong."
Finally, please do not use expressions such as "ur". The correct word is "your".
Student or Learner