I have about two bibles for every three years of age, and I treat all of them with great respect. It is my opinion that nothing should be put on top of a bible, except for another bible. The reason for this is that it is a symbolic action, and, contrary to modern popular belief, symbolics do matter! If I symbolize my belief that the Bible is the most important book on Earth, period, it somehow convinces/reminds me of the fact every time I put one away - I do this, because the Bible is the Word of the Lord.
As for putting a Bible on the floor: I have two of them beneath my bed, mostly because I always read/study/think/work in bed. At the moment, they are accompanied by Spurgeon, Edwards, Immens and Dr. Humphreys; they are in good company.
I also never take notes in my Bible, but that is because I never take notes, period. Not at lessons or lectures or sermons, or in books, and therefore not in my Bible. Usually, if I think something is worthwhile, I memorize it. If I'd take notes anywhere, it most probably would be in my Bible. One of the more robust ones, that is, for my main Bible, which is a wonder and unicum in the art of bookprinting, might tear were I to do that.
As for general neatness, I am pretty strict on that with all books, and even more so with my Bibles. I lent two of my older Bibles to my younger siblings for use in church until they had/have their own Bibles, and made very sure to instruct them on how to use it, and how to use it carefully. They still look good.
I think all of this boils down to a simple question/thought: "How can you profess to set great store to the things represented in the Bible, if you cannot bring yourself to set great store by the Bible itself, which is a far smaller thing to do, and much less inconvenient (from a worldly point of view, as following the Lord is in all ways profitable)?"