Is there anyone else with a movement reduction spell? If not, then yes you need to worry about rooting unless you like large trains caused by runners.
If someone else has a snare/root/Selo's chains/etc then they should handle the responsibility since you'll typically be stunning, lulling, etc with your mana.
Double doors are a royal pain in the ***. I assume we're talking about Takish'Hiz adventures. Best advice I can give is to open the doors, use F9 to change to a distant 3rd person view, then pan around to see what's around the corner. Even that is lengthy, annoying and requires you to get close to the door. Another option is the have a mage/wizard use the Eye of Zomm line to scout the room and you /assist the the caster to lull the adds. Lull doesn't require line of sight so this works, even if it is lengthy.
Best bet, of course, is competent crowd control. Let the door mobs rush ya and mez the bastards