Q1. Usually12 High Card Points but you can open lighter with extreme distribution. 6-5 can be opened with as few as 9 pts.

Q2. 6+ maybe 5 if you have both majors but never less.

Q3a. 29
Q3b. 25
Q3c. 25
Sometimes you will make with less sometimes you will go down with more.

Q4. Partner should have a balanced hand with 12-14pts. Less than 4 spades.

Q5. 4

Q6.1NT 16pts and balanced. Take no notice of useless doubleton. 1NT is very descriptive and there is no guarantee you will finish in NT anyway.
 
Q7. 4H.
 You have enough points for game and a fit - so what else do you need to know.
Later on you wll learn a more useful bid for 4 H's.

Q8. 5 or more never less.

Q9. 40 points in a pack, partner has at least 12 of them therfore you can have up to 28. This is why the bid is forcing

Q10. At this stage partnner should have no more than 3 D's, at least three cards in every other suit. If he bids again then he will have 16+ and a different shape. It is not illegal to pass but this means you think 1D will not make. To do this you would need a signifcant number of  good  Diamonds. It would be most unusual!!