I use Constant Contact for an organization that does not want to grow our list or sell anything. We have a set group that we manage on our own and Constant Contact default settings don't always mesh well. We just want to communicate information to this group. I'm sure we aren't the only organization in this situation. Constant Contact - please consider this kind of experience! (example - a sign-up or tweet this button as a default with no option to remove)
We apologize for any frustrations you're experiencing with your account. We have many clients similar to your situation who utilize our services for various reasons. Thus, we understand that you may use our services differently depending upon your marketing and communication goals!
I also wanted to share that you can easily copy the link for your sign-up form and use it to create a button in your email campaigns. In addition, you can make it easy for your contacts to share your email campaign socially by inserting social share buttons, including one for Twitter. While these aren't automatically included within every email template you can manually add them. What's more, utilizing a master template is a great way to ensure both buttons are always included within all of your future emails!
We'd love to know more about any other specific default settings that aren't working for you so we can help make using Constant Contact a better experience for you. Please let us know if there's anything else we can help with!