Personally I think they could move teleport to a boot upgrade like they did during Bildgewater.
I also think they could do it with ghost as well.
I'd like to see more variety in summoner spells though, things like damage boosts that would help out some champions -
or allow barrier to grand a small % of armor and mr with its activation for tanks.
Some of these could just use some small buffs. Like Barrier being something like boost Armor/Mr by 2% on activation.
Flash is fine,
Ignite could use a bit of a bonus - it falls off too hard late game, possibly something that scales with your level like "Burns the target for xxx true dmg, also enables auto attacks against target to spark ignite and increase duration by 1s." as it is, we've all had that moment when you ignite a tank and just cry as your summoner spell is proven to be utterly useless.
Cleanse should boost tenacity, Tenacity should be re-introduced into the game. (I know we have boots and masteries, but lets be honest here - Theres basically no outlets or entrances for tenacity on champions that are not tanks.)
Adcs used to have zephyr.
Now they don't have that.
Cleanses, or items that allow or have a cleanse on them - should give tenacity.
Mercurial should give +10% tenacity with it.
Mikael's should be +10% as well.
Cleanse the summoner spell should "Remove all debuffs" (Cleanses should remove ALL debuffs, not just CC.) And boost tenacity by 10% for 5s or something like that.
Exhaust is great as it is.
Smite is fine.
Heal/Clarity should be combined into one summoner spell.
Nobody takes clarity becuase nobody needs the mana that wants the mana late game.
Give Heal "Restore 20-40% of maximum hp (Based on level) and 20-40% of maximum mana (based on level) to you and an ally.
then they could go in and add some NEW summoner spells.
"scare." your champion screams, briefly fearing all nearby targets for 1s and making them run away from you. (Can be a defense/offense/tank spell.)
"crumble." (This would be one for split pushers.) Your auto attacks deal(2-5%) more dmg to structures. While ignoring their natural defense stat.
"semblance." Briefly channel this spell then mark an ally, you take a portion of all dmg (possibly 2-5% at max level) that ally takes. (Can be taken to pair with bond of stone, like how deathfire touch can be taken with ignite.)
Theres so much potential for summoner spells to truly do alot for the game, just a way for people to make their unique mark on the surface of league.