Yes, you can toggle tweeting on and off by clicking the blue Twitter bird on the post form.
Yep! Just hover over the Twitter bird to open the text field. Be sure to leave a space between the last character of your tweet and the [URL] or else the link will get messed up.
First you’ll need to install a theme that supports the Twitter widget, like the Default blog theme for example. Next, make sure your Twitter and Tumblr accounts are connected by following the instructions above. Finally, configure your theme settings at tumblr.com/customize.
No, there is no way to control how your Tumblr posts look on Twitter, so a tweet may or may not have an image preview attached.
Tweeting might be delayed at times due to network issues. Also, make sure the Twitter icon is blue when creating a new post. If it’s gray, that means you’ve turned off tweeting for that specific post.
We recommend removing the Tumblr application then re-connecting. Go to https://twitter.com/settings/applications and click “Revoke access” next to Tumblr, then complete the connection steps above. If that doesn’t help, make sure you’ve enabled pop-ups on your browser.