Cleanse is fine. It gets use regularly on Vayne and other slippery champions against CC heavy teams.
Ghost is fine, the champions that actually value increased move speed use it over Flash.
Revive is fine, it has been a viable gimmick pick (Along with TP) for ages on Karthus and other 'Jump in, burst, die' type champions. If Revive was any better if would be getting into the OP end of broken rather than the broken but kinda functional in the right situation end of broken.
Now, the other two? CV used to be super strong, but bot lane is so volatile now that you need two combat summoners or you lose lane so it can't go there. Top lane needs TP, or gimmick Ignite kill lane. Jungle needs Smite. So, mid laner who isn't aggressive enough for ignite and doesn't need an Exhaust to deal with an assassin is the only place I could maybe see it going now... Which means it is dead. They would have to buff it a HUGE amount to make it worth the summoner slot.
Barrier just needs a small numbers tweak. Slap 50 more HP on the base shield or drop the cooldown by a bit and it is good. Heal is just better right now. Small amount less HP, but the heal HP sticks on you and barrier is temporary. Heal also affects 2 people, and has a strong move speed buff on it. Barrier needs to find its niche compared to heal.