Of COURSE you can! you will even find it easier in some instances because once locked on, Combust needs no aiming, Soul Steal kinds follows, Fireball is hella-fast, and Lightning arcs from the hip, so to speak. Slow Time, Clone.... You just don't know how versatile you'll be 8^)
As for Impale, I just don't recall.
Great way to test would be to save, use the magic cheat three times, then check it out.You just wouldn't have the advantage of the fast refilling mana that usually comes from sinking your points into the Magic skill.
After you find out, use the cheat again to cancel it out... or reload from just before.
"Great Gulgren's Sack!"