Help please! Is extracting an abscess tooth dangerous?

It can be... I usually recommend antibiotics prior to extracting an abscessed tooth. I recommend this for several reasons. First, the antibiotic reduces the infection significantly. Second, with less infection, the tooth can be more adequately anesthetized which makes for a more comfortable extraction. Third, following the extraction the comfort level is enhanced with less infection present.
No. Probably the best thing you could do to get rid of the infection that is in you.
Not if. It is removed by an experienced and trained dentist, any medical conditions requiring special treatment are followed, and you are covered with the proper antibiotic. The sooner it is removed the better! discuss your concerns with your own dentist.
Depends. Depending on the size and location of the abcess, it may be advantageous to take antibiotic to treat the infection prior to extraction. Frequently, it is fine to extract a tooth that is abcessed. Your dentist can determine what is in your best interest for your specific situation. Don't worry!