From my research on this herb it can cause anxiety as much as help mitigate it -- depends on the person. Personally, don't care if natural plants are legal or illegal, never believed you can make something nature grows illegal, it's not like a drug manufactured by humans that nobody has experience with and the body has no idea how to digest, but again, my research on this plant shows it's probably a risk for anxiety sufferers. I guess you don't know until you try it, but again, it appears to be a difficult herb to use correctly. Probably for the strong at heart more than the anxious, just like marijuana, which is also illegal but who cares? More important, it tends to bring out anxiety in those prone to it, so one has to be careful.
Not a good idea. For one, if it's illegal where you are, it's illegal, not worth it. Secondly, it's habit forming Search the addiction forum, you'll find plenty of people who ended up with some bigtime problems thanks to kratom.
There are MANY othjer routes you could take to treat your anxiety...that's not one I would recommend.