Even without blink, the monk could dimension door out of the web, and then at a 200ft charge rain do his snap kick/double stun shtick. Or he readies a partial charge when the dragon gets near to breath, exchange double snap kick attack for one breath weapon. Dragon does not win this exchange.
Blink reduces the damage, but Entangling Exhalation is not about damage. Lets put the math in here, 7d6/2 = 31.5/2= 16 damage. Plus another 1d6 per round for the next (average 2) rounds. It's not a Web. The Entangling Exhalation feat entangles you for 1d4 rounds, not an area, you the target. You cannot blink to escape it, and it lowers your movement speed preventing your Winged Vest from reaching the height the dragon can spring attack from. So once you have taken any damage from the breath weapon, you can be kited to death. But you don't even need to be, the above damage reduces your HP below the threshold of being killed by 50% of the damage from a single full attack action.
Also, when you attack, your two attacks have a 30% (21) and 55% (16) chance of missing the dragon, even if he is flat footed. You likely miss at least one of your attacks per round, giving the dragon the same 50% damage reduction you have. Decisive Strike gives you a single attack as a full round action, doing 24d6+20 averages out at 104. 70% of which is 72. It takes you on average 3.5 rounds to kill this dragon. It kills you in 1-2. You can't win a straight up punching match without some luck.
You can in fact Blink out of the Grapple, which does make that part obsolete. However, if you lose initiative you do not have Uncanny Dodge. As such, on your first round of combat, you are flat footed, meaning
you cannot take an Immediate Action to activate your Blink ability in response to the Dragon's attack, and therefore explode.I would not (and it would be in my opinion a dick move) to make targeting opponents' saves require a knowledge check. It is fairly common sense in a world such as this that the guy in armor probably can't dodge well, the guy dodging around a lot and sneaking probably isn't tough, and the raging barbarian probably doesn't have a lot of self-control.
You keep mentioning "I would do X" or "If I was DMing I would do Y" but that doesn't matter. What you would do does not have an effect on how powerful the monk is in a neutral setting. I am ruling based on pure numbers, I don't care about metagaming at this point, we are running numbers. You can make a house rule that you can't go to the bathroom without a Knowledge: Bowels check, but it doesn't effect class balance on a global scale.
JaronK's ray has only a 55ft range, yes. But the dragon has to be within 50 feet to effect him with anything. A readied action from JaronK can put a beam in the dragon's face if he was to try. Regardless of being Entangled. He also still has over 2000 gp left which is plenty for a couple of scrolls or items which can use "Assay Spell Resistance" to make both rays unstoppable.
In your case, if you are Entangled, you have no way of reaching the dragon. And if you use your surprise round to charge, you did not Enlarge, and cannot trip the dragon at all even if we assumed you could trip a flying opponent (which is kind of silly, and I've never read anything which said you could. I'd like a link.) Also if you did not Enlarge, you do about 33% less damage, making killing the thing a 5-7 round affair.
Also, where are you getting a +9 Initiative? You have 4 from Improved and no Dex.
@ Tenacious: I tend to agree, hell he's got no Hide in Plain Sight ability, and the chamber the dragon is in might not have any cover, I'm not seeing how he's always getting the drop on it.