There are a number of questions you are posing and some don't have straight forward answers. They depend very much on who your registrar is and how much access your hosting provider offers. The old saying of; "you get what you pay for", is never more true. You can't expect decent control on free or almost free hosts. They are designed to give you minimum flexibility and hook you in, in order to upgrade you at a later date to a more expensive option. Keep in mind also, some of the larger providers have European servers. So it may be a US company, but your site may not necessarily be physically hosted on US servers.
That said, your site is a minimal size in today's terms - almost minute! So as far as hosting in the USA is concerned, you would suffer some delay, (known as latency), but it probably wouldn't be perceptible.
Your second question - bandwidth, refers to the amount of data transmitted and received at the server. This will be directly affected by how popular your site is (number of hits) and the content. Clearly streaming video is far more bandwidth intensive than text files, but given the size of your site, it's more likely to be the later I would think. Hosts have the ability to measure the amount of data transmitted and once your allowance has been reached, often charge extra for exceeding that allowance. Sometimes by x amount per 1GB. Generally, there is no restriction on how often you can make changes.
The www. issue, is nothing to do with hosting, but is a function of the way your DNS entry is set-up. If your registrar is the same as your hosing provider, that may be available at the control panel for you to change. But WARNING; don't mess with it if you don't know what you're doing. Getting it wrong, can make your site disappear from the web. Depending on how much access you have to the back end and if it's a Linux server, you can also control that by using a .htaccess file in the root of your site. Just use a redirect regular expression.
Email addresses again, depend on how your host provides access. It's not uncommon for them to be restricted in number with the cheaper deals. It would be as you said; [email protected], [email protected] etc.
Most important with these cheap deals, read the small print and understand exactly what you're getting. More to the point, understand exactly what you're not getting!