Are there any web interfaces for distribution rights to the trac, SVN, SFTP?
To the right of the listed services could easily edit the man who does not make friends with the console?
Trac admin web-UI already supports permission groups and assigning allowed actions to both groups and individual users.
For setting more fine grained permissions you'll want something like FineGrainedPageAuthzEditorPlugin (general), for repositories TracSvnAuthzPlugin (simple) or SvnAuthzAdminPlugin (advanced).
If do not use existing authentication infrastructure of your web-server you may want user/account administration inside Trac too. Look at AccountManagerPlugin. A common way is to let it manage a central file in htpasswd or htdigest format, that can be used by multiple services, even across several Trac environments, if you like.