I've had Twitter accounts suspended, you can still log in and make an appeal through their site to get your account unsuspended, if they decide in your favor.
You can never actually talk with a real person at Twitter, it's all done by email and online forms. Really brutal.
You can get suspended and not even know why.
I had two accounts stolen from being hacked in my email, and Twitter was no use in helping me get them back, didn't even really care. Their reply is basically "the email you're contacting us with does not match the email of the Twitter account you are inquiring about". Really? that's because the hacker switched the email. doh!
So yes, use Twitter and free email and all that but realize your accounts could be vaporized at anytime, and as these large tech companies deal with 100's of millions of account holders who aren't paying for the service, they could care less to devote anything more than the barest customer services resources to it.
It's amazing how much social media usernames can sell for when you realize they can be taken away or suspended at any time.