splitting hairs?

when i started this blog (3 years ago!), i decided not to worry about capital letters, be it for the pronoun 'i' or the beginning of sentences. but sometimes i've been uncertain: if i put capital letters for names, then surely those words that also always take a capital letter (days of the weeks, months) should also keep theirs. but then the inconsistency annoys me. having read and enjoyed the book 'Eats, Shoots and Leaves', this question has come to haunt me. should i forego capitals entirely? i used to get pissed off at people who wrote SMSs in code: CUL8R - what does that mean? when i used my mobile in Japan, i always wrote with capitals and full punctuation. once in a while i would abbreviate a word or two, but capitals and punctuation stayed. now, i realise that not using capitals at the beginning of sentences has become a habit, as well as the lower case 'i', and that that's how i now write most of my emails. sometimes, i wonder if people (my friends) will think ill of me for that. i used to pester about all the shortcuts that people made and that would undoubtedly result in poor spelling through lack of practice. am i splitting hairs? i know i am. is this important? probably not. still, i have to make a choice, and it's a hard one to make for someone who can use semi-colons...