This is incredibly hand-wavy. For one thing, speculation about which days of the week are "better": Every single day, seven days a week, for any given moment in time, there are the same number of items on the front page. Does anyone have data on (for example) average numbers of upvotes varying in a statistically significant manner by days of the week? For another, data about how many characters in HIS titles correlat…
Re: data about title length: Since I have a database of all HN submissions, I spent a few minutes to check. Turns out that title length (for non-1-word submissions) has no significant effect on submission score at all: http://i.imgur.com/1zthOwS.png
Nice chart! Yes, my sample size was rather small, so it's difficult to make absolute conclusions, but it was interesting to see a definitive correlation between post length and upvotes!