I would recommend against using a and d as targeting binds, I know some people do with great success but those should be used with abilities you will use a lot or for more timing specific abilities like cc. Speaking strictly from a healers perspective, I've had a lot of success using mouse wheel for targeting friendly players since it allows you to move AND target players for preheals/instant casts heals, etc while also being able to move easier against cc. Mousewheels also scroll quicker than any button press ever could (and is more of a fluid motion scrolling up or down THEN pressing the button vs pressing the button and pressing another one moving the hand) which is especially useful against swaps and such. then for targeting arena players ideally you would want to use a mouse with a few extra buttons but you can easily get away with alt/shift/control modifiers for 1-3/5. mousewheel is also perfect for premades (assuming 2/3 other heals) you can have mousewheel assigned to the other healers and fc (I use shift modifier) while still allowing ease in positioning to assure you remain behind the dps but can easily swap as well. It helps a lot with brain lag. Trust me. This is assuming of course people use either q/e or a/d to move, but what kind of nonsensical person wouldn't use the beloved wasd? D: Also caps lock is the perfect bind for judgment... You may accidentally yell a lot though.