Adding water after fermentation's started is usually not a good idea for a variety of reasons, the primary one being that it's very easy to infect your beer. Your hop utilization also goes out the window.
Next time a beer seems too strong, just bottle it once fermentation's over and put it...
I have my system hooked up to a manifold with multiple kegs force carbing (set and forget) and several kegs connected for serving.
My brewing partner believes that our weekly parties serving beer slow the carbonation process. However, there is no noticeable drop in pressure. It seems...