PAX Pokemon League

I started working on the pokemon I need from the safari zone during my idle time. I've caught all the plains ones, so I understand the days required and item placement. I have two questions though:

1. Does it matter if I have too many of a placed item? So that I could be farming for a few things at once with the multipliers.
2. Do some of these have less than 1% occurrence? I was looking for about 20 minutes earlier and didn't see one Riolu in Meadow with 10 trees and 14+ small rocks.

If your looking for a Riolu, I can probably get you one. Trading might be easier than rooting around the Safari Zone.

I think it's just trying to catch 'em all that's infuriating. Personally I didn't bother with the Safari Zone because it was so irritating but Serebii has a very extensive and in-depth guide on the thing. Here's the link [urldk6]http://www.serebii.net/heartgoldsoulsilver/safarizone.shtml[/urldk6].

I keep getting phone calls saying various places have changed. It has been a few weeks since I put the objects in Safari zones, so perhaps some of the timed pokemon have come out.