Without contractions

I have tried, for a number of months now, to eliminate all contractions from my writing. This includes my dissertation, all text messages, and facebook and blog posts. I have also tried to no speak using contractions, though admittedly this was a bit tougher. My interest was peaked after seeing "True Grit" and hearing the unique, albeit almost poetic, way in which the characters spoke.

Two things arose in my thoughts. First, I should try and write, and speak, in a less contractual style. Secondly, how accurate was that style of speaking? As to the latter, here are two sites (the first links to the second) describing the use of apostrophe contractions in the English language. As the second points out

True Grit (the novel) has definitely got a lower frequency of contractions than the other two works, even though it's not in fact contraction-free; and this pattern is not a true picture of the 1870s southern or south-midland vernacular that its characters (like Mark Twain) presumably spoke.

If True Grit (the remake) has an even lower frequency of contractions, its picture of "how people talked in the period" is even less true, at least from the perspective of mere historical fact.

Despite this historical fact I still find the absence of apostrophe contractions almost liberating. I feel somewhat freed from normal (contemporary) linguistic conventions, and I enjoy the way this liberation sounds. I will try and continue to exclude contractions but the second website implicitly hints that certain contractions are certainly more common (it's/it is; that's/that is), and, for the lack of better wording, I find them linguistically more fluid as well as helpful.

PS We write the uncontracted form of "can't" as "cannot" [no space], but we do not write the uncontracted form of "won't" as "will not" and "don't" as "do not" [notice the spaces]. Why is this?