Depends. If they are healthy, functional, and esthetic then they are fine. If they are not , then you may wish to have them removed and implants with crowns placed. The most critical concern is the preservation of bone to allow implants later if you choose to keep the teeth now. Also depends on location --front or back. No set rule. Ask your Dentist for options. I have patients in 60's with baby teeth.
No problem no pull. At this point, unless they are causing problems (functional or esthetics) you nigh be better off leaving them as they are. If you pull them, then we would need to consider replacement options or space closure options. Consult a dentist AND an orthodontist to see what your best paths would be.
See your dentist. Sometimes baby teeth don't loosen when the permanent teeth come in. Your dentist may want to pull the baby teeth to give more room for your permanent teeth and prevent crowding.
Depends. Whether or not to pull remaining baby teeth depends on whether they are in the front or back of your mouth, how much of the root is left , whether they are in good position relative to the bite plane and will the spaces need to be replaced.
Sure. sure they can be pulled if that is what is needed but you need to be educated and informed about your options for replacement if that is what you wish.