Here are my answers to your questions. Others here may see things differently. If so listen to them.

1) Each has it's advantages and disadvantages. Plants in pots have one big advantage. You can move them. If you have a totaly safe spot with good dirt, in the the dirt is the way to go. Much better yield, more room for roots, and less trips to water. Also in ground plants are in the envionment the way nature intended.

2) Keep your eye on them and tackle any problems as early as you see them. As problems occur try to fix it with natural methods. If those do not work, go to store bought remidies. The only exceptions I can think of where store bought is better is slugs/snails.

3) Skip the hormones.

4) Any plant nursery should have them. Our Lowes here have them, but they are in the back of the store. Ask around. They are easy to find.

5) Each grower you ask will have a different answer. This site has a fantastic archive. Go back and every question you ask will have many specific answers. No offence intended, but its not like you are the first one to take this ride. Most of your questions have been asked and answered here many times over.

Good luck.