Try this for the TopicView template:
<img src="/desktopmodules/activesocial/profilepic.ashx?PortalId=0&uid=[AF:PROFILE:USERID]&w=32&h=32" border="0" />
As for the Twitter Widget.... Assuming that the button is referring to a specific post, text=[SUBJECT] would probably work.
The URL is a little more tricky. Unfortunately, the [SUBJECTLINK] and [TOPICURL] tokens do not render in the TopicView template.
You may need to manually form part of the url, but it SHOULD work like this:
http://{www.domain.com}/{TabName}/{TabName2}/tabid/[TABID]/aft/[TOPICID]/Default.aspx
You may need to URL encode it, since its a url inside a url, which would look like this:
http%3A%2F%2F{www.domain.com}%2F{TabName}%2F{TabName2}%2Ftabid%2F[TABID]%2Faft%2F[TOPICID]%2FDefault.aspx
Unless you are using AF vanity URLs... in which case the widget would show a less than accurate amount of tweets, since no one would be linking a URL formed this way (unless they click this button).