I'm so tired of that question. No, I don't use a macro. Watch my other videos and you'll see the variety of spells that I use, along with the mistakes in casting. In fact, around :58 seconds, you see where I miscast. My pattern with elemental missiles for freezing enemies is sdfq, sdr, sdfq, sdfq, sdfq, sdr (steam, cold, steam steam steam cold, steam steam steam cold...etc), but you see where I miss some keys and send out a fireball that unfreezes the giant trolls. It's all key-pressing procedural memory.
Different keyboards allow different amounts of buttons to be pressed at once. My keyboard will accept at least, based on magicka, 4 keys. I press the keys all at the same time, or roll my fingers through the key presses from left to right (an ability I developed from playing lead guitar for 11 years).