I'm not sure about Frightful Delusion . It seems like a worse mana leak that the cost will very often be payed. I understand mana leak is going out, but I suggest looking for something else. I havent tested it myself, but Second Guess ?
I think the main problem with your deck is it's a little too busy. A lot is trying to go on at once and as a result none of it happens as well as it could. I'ld cut all your Invisible Stalker s and your Latch Seeker s because with not a whole lot to boost their attack they are not going to be a major help. They also can't get the boost from your favorable winds. Then I'ld cut the Silver-Inlaid Dagger s and the Mass Appeal s (not a lot of humans). This gives you 11 cards to add. Like you had said, if you want to flip delver you need more instants and sorceries. Vapor Snag is awesome, helps you stall to cast your big stuff, maybe put in 4 of those 3-4 card:Talrand's Invocation, 3 [[talrand, sky summoner] and maybe another Midnight Haunting
Sleep might be good for you too actually. Gives you a clear field to swing at and nearly no fear of being attacked afterward.
So this seems to be alot like the deck I run, which runs very control based and then on turn 3...BAM the creatures are all set up and slam face by casting midnight haunting on your turn then on my turn 4 I cast two anthem cards and get usually 5/5 flyers with vigilance and hexproof :P
delvers, drogskol captains, midnight hauntings and lingering souls, get some black mana in there, not too much, only 3 works for me (1 swamp, 1 drowned catacomb, and 1 isolated chapel) to flash back the lingering, some honor of the pures and intangible virtue...your tokens are the main point of this deck, they really hoarde the field and ramp power up fast
if you can, 4 phantasmal images are a must, get a copy of your captain and both become hexproof
dungeon geists are a great thing too...they get your favorable winds buff, captain buff, and they tap down massive tanks during heavy games
and last but not least...mana leaks, replace your dissipates for these..one turn earlier to cast, and unless they run mana ramp, they can't stop the counter until turn 5-6, when you should have won....
tendeem lookout isn't needed, your draw sorceries should be plenty, same for your sphinx, and nearhearth pilgrim is nice, but you don't need the lifelink...temporal mastery isn't needed, you literally pay the miracle cost and it either turns into another attack or another land....it really is not worth it, also, as for karna dn batterskull...same thing, focus on teh instants, sorceries, and spirits (if you want the spirits)
You can keep sleep, it is quite nice as it does not target like dungeon giest does and can become a win con card...hope this helps!