I would remove the emails from the post unless you like spam, as this is a publicly available forum so it could get harvested.
Downloads of what, I don't know of any downloads that are email required ?
You should be able to change your profile settings, email address soon 20 posts is a requirement to make certain profile changes. Though I'm not sure if you would be able to change email sooner, check the Profile, Account settings and see if you can access the email field.