In a perfect world, pro healers and noob healers would keep their groups alive equally and there would not be any way to distinguish them apart...
Unfortunately, that's not the case. Some people are simply out of their elements when it comes to healing. Just the same as few people make excellent tanks. People have individual and different skill sets that make them unique on how they play and what they bring to a raid or group. Which happens to be in your case. Which happens to be in my case. I'm a petite female that cannot reach the extent of my keyboard w/o moving my hand... however; I have learned to adapt.
Not every class is made for everyone; if you have difficulty playing one... play another. We can not expect everything to be made easy for us every time someone is experiencing difficulty adapting.
Sure, mouseover healing is makes healing very easy. Has lots of benefits... especially for raid healers. The fact is, that was in wow. Everyone has moved on and are about to switch game , right? Do it feet first and embrace the new game, folks. Everyone wants a new game but refuses change.
You make good with what you have. Life gives you lemon; you make lemonade yadiyadiyada...