What I do, is that I make mouseover macros for my healing spells, and bind the 2 most useg ones to scroll up and scroll down. 1-handed healing anyone?

You are playing a paladin... you could probably heal by rolling your head on the keyboard.
Seriously... spam flash, occasionaly holy light and/or throw the odd instant heal... oh yes and cleanse ofcourse (why do paladins have 1 dispel spell while most other healing classes have a different dispel for every kind of debuff?)... that's err... 4 buttons... and 2 cooldown skills (one for less mana use and one for forcing a crit heal).
Let me count mine... hmm... rejuv, lifebloom stack refreshing, regrowth, swiftment, abolish poison, remove curse, nature's swiftness, innervate, healing touch... and i need to keep track of hot durations on different partymembers...
Do i really want to do this without an addon? No!
It would be like trying to fly a plane without instruments, possible... but would you like to be a passenger on one?
Don't get me wrong... i'm not saying druids are hard to heal with... but having some timers and a clicking addon makes it so much more relaxed.