First of all, yes, birds can get drunk from eating overripe berries. As the berries ripen, and then overripen, the sugars get converted to alcohol. Isn't that a surprise?
And of course, once the birds figure out that the berry harvest is on, they will stuff themselves and voila - birds which can't perch on a wire and can only peer at you from one eye because they are on their sides.
As for the geese: another vote for Sno's observation that more geese will simply move into the now vacant habitat. And another vote for the stipulation that Canada geese in Madison are pests. However, both of those votes are subject to caveat - there wouldn't be such an overabundance (which would negate both of the above) if they couldn't reproduce in a completely unfettered environment. They have next to no natural enemies in an urban setting. Aside from the occasional road kill, about the only predator which might grab a few goslings are snapping turtles. I can't even recall seeing a road kill goose, everyone stops for them when they cross roads, even truckers. When you consider that in a "life is good" world, Canada geese can successfully raise 8-12 goslings per clutch AND they can get around to two or even three clutches in a season, you can do the math and figure out that they are just like humans in overrunning the environment.
I think the judicious thinning of the flock is an excellent idea and should be a regular and, for the forseeable future, a frequent occurrence.