I need to expose my computer to the security risk of the entire internet, even when I'm playing with people in my *own* house?
Yes but it is a lot safer than a WAN through LAN because your computer automatically treats everything with suspicion from the Internet but often trusts stuff from a LAN. WANs as such might allow total strangers unrestricted access to computer files if you were not aware of the implications of using them.
Tell me again how this is an "improvement" for the customer?
Before you needed your friend to either...
* Come over with a computer (not everyone has spare computers or as many computers as friends).
* Buy the game to play through BattleNet from their homes.
Seeing how the first point is mostly out of the question for most people, the second point is drastically improved upon as now only 1 of a group needs to own the game.
I'm sorry if you've never known the joy of actual LAN games with actual friends, but the faint online experience doesn't even come close.
I think you are just making up stuff that is not truly there. Playing with someone you know is the same whether they are in the same room or in a different home. If you really want them in the same room, you still can have them since most internet connections are LAN wide now anyway and the bandwidth an RTS game uses is minimal.
Slightly related: my battle.net account (that I had to create for some stupid reason I don't know) has been locked because of "suspicious activity", aka "hey our stupid authentication system is stupid as fuck". At this point I just can't be bothered mailing my ID to verify my account. I just don't care anymore.
That occurs when ever you change IP domains spontaneously. An example would be logging in mostly from home and then trying from your University. As the IP domains are very different it locks your account. This is one of the many forms of protection Blizzard uses to stop hackers.
What makes me concerned is you said "mailing my ID to verify my". Blizzard never asks you to mail them anything. If it truly says mail your ID, then that means it is a scam email and your account is not locked.
To restore a locked account.
1. Go to BattleNet website from the IP domain you want to use the account.
2. Try and log in to the account using their account management.
3. You will be presented with a choice of ways to unlock the account.
3.a. Enter the licence of a game attached to your account. If you brought a physical copy of a game, this is the way to solve it as you simply open the case and re-insert the key.
3.b. Enter your secret question. This is how you unlock accounts with no games on them.
4. After completing the above, Blizzard will send you an email with a link to reset your password. It will ask you for a new password that has to be different from the old one.
5. You can now use your account again.
It takes under 5 minutes to do the above. It is not even Blizzards fault they added that form of protection, blame the hundreds of hackers that try and steal accounts and ruin the fun of people.