*Laughs* it's only what, 5 accuracy? It'll be fine. However, I do wish to bring something up.
Future Sight is currently on par with a few of the "huge power no drawback" moves, such as solarbeam. When it is an option, people will take Future Sight over psychic (and it is a common option). In fact, Future Sight is one of the few moves keeping some pokemon viable/useable. I will warn that lowering Future Sight might make those off-the-wall pokemon less viable to PvP, however. (They are uncommon right now, but not rare.)
(Pokemon that will take Future Sight over Psychic: Alakazam, Espeon, Xatu, Gardevoir, etc. The only psychic pokemon that don't learn FS but do psychic and might be useful are Slowbro/king, Exeggutor, and Gorebyss. [lol gorebyss])
So as an experiment, I don't think there is an effective testing pool to work with because of how uncommonly I see those specific pokemon in battle. In other words, there won't be much feedback to receive. Unless that was your point, in which case I can't say I understand. =P
I would instead work with Brine, because Hydro Pump would make sense as its "Step up" option. (Like with Psyshock and Psychic, here.) Brine is unnaturally edited anyway, it has a high BP because of its situational useage in handhelds and staff at one point said "Well let's pump up the BP to make up for it." So instead of 60 BP with it doubling in power under certain circumstances, it has 97 BP and 100 acc. (This could basically affect Lappy, Kingdra, and maybe Starmie/Cloy instead of 2 UU pokes.)
But that might also tick people off, so...
*shrugs*