First off, Yes, I did do a search, & didn't feel like browsing through 62 pages of replys.
Now, How long is needed to see the Canyon, No, I don't mean the Chevy Chase Head bob tour, & I know that if you want to see every rock & sunset, you could spend a month there, but could it be done comfortably in say 4-5 days?
We don't do LONG hikes, so hiking is not a major time consumer.
Since you stated that your not into long hikes the rim trail is for you, its fairly flat and sometimes you can come across some of the wildlife.
There are many things to see at the South Rim without having to any real hiking. The North Rim is closed during this time of the year, but is well worth taking in when it opens.