Water should be less effective against Ice, methinks. Unless it's a move like Scald?
What about against a Ground/Rock-type opponent, your Pokemon is slower when using the Electric attack? Technically Brock's Onix was able to catch Pikachu before it could jump out of the way, so I would grant it.
I must also reiterate that Charge would only allow the next turn for an Electric attack, not like Miracle Eye or Foresight.
I think the future of Pokemon is basically going to involve elements which were commonplace in the Anime, and you could choose between playing Turn Based or Real Time. Therefore in Real-Time certain moves could clash with one another like if both combatants chose Psybeam, Water Pump or Thunderbolt. So granting an ability to Charge like what I propose wouldn't be stretching it further than what I envision