- Pies appear every 60 to 80 seconds, independent of level
- Every minute or so, a pile of bricks falls down, after level 3, and never more than 3 per level
Yeah, these things happen much faster in the official arcade version, unless what you're saying is that these are what you're going to change the game to do optionally. The brick piles always fall down very early on, and I don't believe it's ever taken a whole minute for a pie to appear, though I never see more than one pie per level, and the likelihood of a pie appearing may depend on the floor: I've found it's very rare to receive a pie on the bottom screen, for instance. Did you still need more documentation on the exact numbers of each kind of obstacle per level?
The ways other versions of the game make it harder, by implementing a 60-seconds-to-Game-Over timer and making Ralph's bricks increasingly likely to take out more windows, would seem to clash with the way that you're expected to max out your score by waiting around for a limited number of additional broken windows in the arcade version. Making the ducks speed up according to level number is one thing from the Flash version you could do without too much trouble, although leaving the ducks slow may have been intended to make them more annoying as they linger in your way longer. It's like how making Ralph less predictable could make him harder, or it could just make him waste a lot of time in one place. An instant Game Over for running out of time isn't very sporting, so I once proposed that you could make it a "sudden death" scenario where, say, there are suddenly ducks in all rows, and Ralph keeps doing his super-pound while sliding towards Felix, but that wouldn't work as well in terms of slowly eating lives when there's no mercy invincibility after dying.
So while there may not be a lot of workable methods to make the actual gameplay harder without breaking it, increasing the points-for-lives value is a good idea that many arcade games have as an option. After all, an extra life for little more than two screens' worth of points is awfully generous, especially when most of those points are unavoidable.