1.
your entry titles are controlled by h3.entry-title a {}
(a has 3 states, a:visited, a:hover, a:active, that you will want to color as well.
2.
your post CSS should look like this:
.entry-content {<br />
font-size:1.2em;<br />
text-align:left;<br />
line-height:1.8em;<br />
color:#444;<br />
}
right now you're missing that first period, that's why none of it's working. text-align: left; is what you needed, adding the period just makes it work.
3.
to get your widget titles to change, you'll need to use
h2.widgettitle {<br />
color:#006699;<br />
font-weight:bold !important;<br />
}
i just copied what you had under h2, and added the !important, which forces your style to override the settings from the other style sheet. .widgettitle just makes it specific to widgets. k2 uses h2 for archive pages like http://sublimation.wordpress.com/tag/poetry