You can control their size by limiting growth. My in-laws in Seoul have them at about 7-8 feet inside their home.
Since I have areas in my home where the ceiling is 30 feet high and with sun exposure, I can handle some larger ones. (Already have other trees at about 15 feet)
They're only four or five inches tall right now but in a few years, I should have a decent amount of leaves for my use at home.
Yep, the leaves either dry as leaves normally do on a tree or you remove them and dry them.