This would hide the blog title.
#blog-title {
display: none;
}
To narrow the sidebar take three things. You need to reduce the width in #secondary from the 200px value now. Then reduce the search box (second below) by the same amount and then adjust the % width for the subscribe field. You can set that to a pixel value if you want to match the search widget field width if you wish
#secondary {
width: 200px;
}
.widget_search #s {
width: 194px;
}
#subscribe-field {
width: 95% !important;
}
Some themes do % widths and some do absolute widths, and some do a combination of both. Some use px as their units, some use em units, and some use both. With every theme you just have to do some investigation and see what they are using. The current trend is to go with em units since that allows everything to scale when someone uses the zoom feature in their browsers to increase text size. It is more difficult to work with because em units are based on the base font size used in a particular div or element. It also makes it hard because images are not sized by em units, but by pixels.