First do not use numbers past 5 or 6 as farther than that will force your hand to move which you do not want.
Also bind some abilities to every letters around WASD. If you need to strafe just hold right click on your mouse and use A and D.
I have Q, E, R, T, F, G, H, Z, X, C, V all binded to different abilities, all those letters are right next to your WASD which make them very easy to reach. I also start binding those same letters with ALT if i need more binds, like ALT+Q or ALT+E etc...
Now if you still have trouble moving while pressing your keys, try practicing spamming some of those keybinds while moving, sometime you will have to quickly switch fingers while moving in order to start spamming another ability.
Example: try to move in circle while holding right mouse click and turning with mouse and also strafing, all at the same time. Then start spamming some of your main spells, and once u got it down start doing the same thing but implement your abilitiies rotation.
It will take some practice but eventually you'll get good at it.
Hope it helps!