Is difficult to change the way you play, i once tryed to use a controller (i've played with mouse and keyboard for many year) and i counld't even do my rotation.
"'ve seen a lot of suggestions about remapping strafing to A+D, but that causes backpedaling whenever attempting to move in midway directions." That's why you use the W,A,D only to make your character walk, you have to use your mouse (righ click) to make him face where you need to.
I think the reason to straf with A and D is to free the Q and the E, that way you have 2 more binds.
And for more binds i use: Q,E,R,T,F,G,V,| (the one is left from the 1), and from the 1 to the 5, and the mouse wheel click (Sadly you can't assing the wheel up and down like on WOW). And from then you can use all thos bids but with Shift and CTR as modifiers.
That's how i play, you should a way is confortable for you, so don't rely too much in what other people say, just don't click your abilities.
Sorry if my english is a mess.