If people could only pick one of these spells they could all be balanced around the power of Flash and made better.
Right now I get the impression Ghost is actually intentionally much weaker than Flash so people can't double-dip into mobility. Teleport works sufficiently differently that it has a niche as a secondary spell at least. But I feel like Teleport could be much more interesting if you had to give up Flash for it.
Axests2 votesyou're taking a lot of power away from top laners preventing them from taking a mobility summoner, while leaving every other role unnafected. The reason ghost isn't taken is because the point and click blink is useful in more situations then a movespeed buff. I'd think you're taking way too much power away from top laners just to allow a buff for ghost. Ghost is a niche summoner, and should be, it's been changed numerous times and the spot it's in now while not the best doesn't necessarily mean it isn't good.
Fikule1 votesIf you think Teleport should not be included, that's fair. But it's inclusion or lack thereof doesn't affect whether or not Ghost would be able to be mutually exclusive.
Can you explain why you think Ghost should be niche instead of mutually exclusive to flash and a viable option for those who work with speed? A lot of Olaf, Hecarim and Rammus players don't even bother with Ghost, and they're about a niche as it gets.
Khâmul1 votesGhost is amazing on certain champions,I won't change it!
Fikule1 votesAnd yet, if you couldn't also pick flash, it could be a lot better. Right now you can ghost and flash. If ghost was too good, this would be OP. The downside is that Ghost doesn't even beat flash as an engage or disengage spell, which it should.
Flash's main advantage is quick repositioning in a fight or escaping over a wall. Ghost should do a better job of quickly getting to an enemy running through unobstructed terrain, but doesn't.
Its Scarce Here2 votesAnd yet, if you couldn't also pick flash, it could be a lot better. Right now you can ghost and flash. If ghost was too good, this would be OP. The downside is that Ghost doesn't even beat flash as an engage or disengage spell, which it should.
Flash's main advantage is quick repositioning in a fight or escaping over a wall. Ghost should do a better job of quickly getting to an enemy running through unobstructed terrain, but doesn't.
Okay no, if this change happens it's gonna completely fuck up spell diversity. They are all different for a reason, some better than others yes but in certain situations its nice to be able to choose what you want rather than being stuck with the ghost flash because they're so ridiculously op. The game would be fucking retarded with people just running through walls like its nothing. Summoner spells shouldn't be changed. They're fine the way they are, even if flash is a more dominant spell.
Fikule1 votesHow can you argue for spell diversity while stating you'd prefer 100% Flash instead of 50/50 Flash/Ghost?
No idea what you're implying with "running through walls". You'd want ghost to run through walls? That's pretty much the opposite of what I said it should excel at.
Critmaster Garen1 votesso basically you want them to remove tp and ghost. because thats what would happen. flash is so op, that the other summoners would just never get picked and top lane would be locked down to 
Fikule1 votesSo is your theory that if this happened Ghost and Teleport would remain untouched?
I could see Ghost as gaining an early, larger speed boost that decays and a second of CC immunity. Good for engage or disengage and potentially more useful than Flash in a fight. Like a mini-Olaf ult (but wouldn't actually break cc).
ModWulf Helhammer1 votesMost champions that take ghost don't take flash when they do, soooooooo
St0rmln1 votesI just vote for more balance of all summoner spells. But this isn't a bad idea either