Probably not, since it requires a bit more work than just a keyboard you can buy. I would say something like the CODE Keyboard, WASD Keyboard, or Ducky Shines are good and reliable keyboards.
Probably, but since it is the one of the first to market, if not the first, it's not unusual for it to cost more than what is really reasonable for most people.
Sometimes it's useful to have a preview so you can make sure formatting is all correct and you didn't make a mistake somewhere when writing it. I just think of it of a way to make sure everything is done correctly.
irssi, textual, or IRCCloud (if you care about a mobile client as well) would be good. Textual over Limechat because it is a forked version of Limechat and is much improved in terms of functionality.
The reason irccloud is popular is that it is simple to set up and there is a really great mobile client. No one really needs another web based client, even if it is free; there are plenty of alternatives for that such as ircanywhere[1] or Convos[2].
I'm really not sure who this is for.