1. It hasn’t affected my ability to use a normal keyboard. Using my laptop to type occasionally probably helps with this.
2. Can’t help you, I stuck with QWERTY
3. My favorite feature of my ergo keyboard is the fact that it is split, so I could see the appeal of a split but otherwise normal keyboard. But, I would recommend sticking with the Moonlander. It took me 2 weeks until I was comfortable typing after I switched. Not fast mind you, just comfortable. Then maybe another month until I didn’t have to look down for special keys. Definitely a time investment, but worth it in my opinion.