Summoner spell Rework?

I have felt that some summoner spells are much weaker than others and I feel like something could quite easily be done to make it work better, so after some thought I have some ideas thatsome of you may agree with. I will justify all of them.

Flash - In addition to the small teleport, it should have a 0.2sec invulnerability state. How many times has it happened to you that you flash out only to find that your die out of range of the enemy's attack? This could prevent that and make it fair play. Clarity - This spell should have some sort of cooldown reduction buff, the mana alone isn't useful enough, maybe if it removes 10% of all your spell's cooldown it would be a bit better. Clairvoyance - This spell should definetely grant vision of the seen targets for a small amount of time, its cooldown doesn't really justify its use. Teleport - I feel like the cooldown for canceling this spell is too high, I think it should be 150s instead of 200, after all, you're not using it completely. Cleanse - This spell is most of the times used against cc-heavy teams but sometimes you just have one of those enemies that can burst you out in less than 1 second. For that I suggest adding a 2sec spellshield (like sivir) and IF it gets used, then the original cleanse effect triggers. This would be amazing for those champions that have no defenses at all and keep getting targeted. Ignite - This idea is not mine, I saw it today in a post by @In bed by 6, I think His idea of making turrets prioritize the ignited target is amazing and could be aweasome against those fights where you feel like the turret was an @ss.

That's it for me, keep in mind that anyone would be able to use these spells and noone would be at a disadvantage, other than counter-playing with them.