"Um? Could someone please explain the tearing of toilet paper comments to me?"As an answer someone provided this link which I reviewed as I do all links that come across my blog. Now I find a lot of this to be interesting, but I have to admit that trying to explain somethings such as this and the reason that they are encouraged or discouraged to be tough.
Let's look at this section:
What about tearing toilet paper when there is no option?This is one of those things that I cannot explain without shrugging myshoulders repeatedly because it just doesn't make sense to me. Now perhaps I am missing something but this is a necessity that you cannot do without, unless you are in the woods and all you have are pinecones in which case you are in big trouble.
Obviously one must prepare toilet paper before Shabbos. The problem arises when one has depleted the supply of tissues, torn toilet paper etc. or one is in a place where there is no pre-torn paper.
For obvious reasons we will not discuss the various technical options that are on hand when there is no toilet paper available, but when those options are exhausted and/or one’s only practical option is uncut toilet paper, the following is the correct procedure:
One should tear the toilet paper by resting one’s elbows on the sheet of toilet paper and tear it with one’s elbows. This is called tearing kilachar yad – in a backhanded manner, and is only an issur d’rabanan. 
Ultimately what I find is that there are areas such as this in which I cannot provide a reasonable explanation as to why they are necessary. Some of these things are acceptable to me and some are not. Yes, I am picking and choosing but that is part of life and when it comes to matters of faith I think that we often reach places in which we are forced to use our gut instinct instead of our heads.
That is not a value judgement but an observation.
(Crossposted on Jack's Shack)