Can I have a webform in sidebar block reload current page
This is an old question, but it comes up high in search results, so I thought I'd provide an answer.

The behavior you've described is the intended behavior. The module maintainer states that the original implementation of the No Redirect option was designed "under the assumption that if you were starting a form you'd enter minimal information (such as an e-mail address) to start the form, then you'd want the rest of the form on a larger page."

To achieve your desired behavior (i.e., reload whatever page the block form is submitted from), you need to take one extra step: From the block configuration page, check the box for Show all webform pages in block and save the configuration.