Hello,
I started off with keyboard+mouse, but with the hints from Yoshi (who I beleive is a Keyboard user), I was able to configure myself to do almost everything with keyboard only. It's brilliant! Never have to take fingers off keys, quick access to everything!
The ONLY thing I am having trouble with is selecting an enemy target if there are a lot of them around. Tabbing seems to be very slow, and mouse more faster. That being said, its sometimes hard to click on the target even if its in front of you, so it's a loose/loose situation. (I hear they will make enemy targetting easier in 2.0!)
Note, I play WHM/BLM so may have different needs than others.
(So happy when I mapped ALT-M to 'micro menu'. When being raised, I just go: ALT-M, <enter>, <enter> and I'm up!)
If you are having difficulty adapting to the keyboard, please spend some time looking through the configuration menu and find/create bindings that suit you.
Also dig around somewhere for Yoshi's post on his targetting setup, it works great!
