Sendblaster Opt-in

Hi.
I want to use “Sendblaster Opt-in” plugin for subscriptions in a widget on my dsidebar. And i would like to increase the width of the E-mail field, and to get ride off the Subscribe and Unsubscribe labels (I asume that in that case the subscribe mode will be by default, as it is now). Do you know if any of this things is possible?
Thanks in advance for your help,any suggestion will be pretty welcome.
The site is http://www.eldiadelamor.net