A control Wizard is absolutely a viable approach. There's a reason the Wizard's primary role is controller! My first D&D 4e character ever was a Human Wizard, and throughout the entire Heroic tier I was attacked something like three times -- the enemies were rarely able to attack me, thanks to range, conditions, and forced movement. (I remember one encounter at level 6 against a group of level 11 vampires, where the turn I dropped Hypnotic Pattern every single enemy tried to surround and pummel me... but the HP hit them all and kept them out of range.)
As mentioned, save-ends effects can sometimes be hit-or-miss, as everything has a 55% chance to end the effect at base at the end of the turn, and at EOT you save vs. each effect. The Human's Heroic Effort encounter power helps on that front, as you can reduce it to a 35% chance. (Vision of Death at level 9 can be super nasty if you use Heroic Effort to make them fail the first save, and have a bunch of strikers in the party!) I don't know if there are any monsters with something like the Warden's Font of Life power, but that would make it even harder. That's not saying save-ends effects are bad, just that you shouldn't rely on them sticking around forever.
Zones aren't generally going to expire early, but as with the fire powers you've already got, you have to be careful with any non-friendly zones (by which I mean, a zone which can adversely affect your allies). Phantom Chasm (level 1 daily) is probably one of my favorite Wizard powers.
Walls are good, but most of them will cut off line-of-sight, which would put enemies out of your range if the wall is between you and them. Illusory Wall doesn't have that problem, but enemies can roll each turn they're adjacent to it to disbelieve the illusion.
Forced Movement is your bread-and-butter, letting you keep enemies near the defender(s) and away from you. (I absolutely loved my Repulsion Armor, which could make me immune to non-reach melee attacks once a day.) Forced Movement does put the "tactical" into D&D's "tactical combat," though -- be aware of where your enemies are going to end up, and how it will affect the battlefield.
Then, of course, you've got other spells to help your allies or protect yourself. Phantom Wolf does both! (+1 to all defenses and help set up flanking for your melee allies)
Also: Make note of errata on your spells, as there are a large number. Some spells become more powerful (Phantom Chasm knocks any enemy prone that enters the zone for the rest of combat), while some become weaker (Visions of Avarice only immobilizes on the turn you cast it).