I like your gameplan a lot, and I'm a huge fan of the Snakes on a Plane flying Gorgon.
I think you may find, though, that disciplined players with aggressive decks will find ways to break your Gate before it pays back its investment, and then use that tempo gain to hound your Wizard and try to melee your Wizard directly, while building up a mana reserve. You can always try to race with lightning, but Forcemaster, especially, is dangerous to race because of her Defense and Force Field, and both Warlock and Beastmaster can put out quite a lot of hurt in a short period of time, too.
In my Nonstandard Beastmaster book, I initially had 2x Dispel and 2x Seeking Dispel, but I found, much like you said, that the threat of Seeking Dispel was just as strong as the execution. So much so, that it caused my opponent to reveal enchantments immediately. This often stranded Seeking Dispel in my book, or worse, in my hand. Seeking Dispel is so mana efficient that often my opponent just played around it, and I lost half of my enchantment hate. Long story short, I play 3x Dispel and 1x Seeking Dispel now, and I think it's an improvement.
What's your plan for the mirror match against another Air Wizard or an Earth Wizard or even an Angel Priestess? You've got a lot of cards to delay agro, but if the enemy mage stays out of range might you have a problem?
>Snakes on a Plane flying Gorgon
lel xD
I can definitely speak for what you just said about destroying spawnpoints. Whenever an opponent brings out a spawnpoint I try to destroy it. If you are able to do so before the spawnpoint breaks even you will disrupt their strategy and will have caused them to waste mana.
I used to run Seeking Dispel but I don't anymore for the reasons you just described.
