I once got told off by some woman for putting a bottle in the slot for cans, she just ran off when I pointed out that there was no partition on the other side (so it went into the same garbage can). At old work it was really confusing - they had a bin for 「缶」 and another for 「空き缶」.

The yellow line (点字ブロック) is for blind people. There's usually no proper side to be on (except in stations) so whichever side is fine (unless everybody else is on one side).