1. i fear it's not possible at the moment.
i will see if i can easily introduce an [event] to let you exclude anything from the log, in next versions.
2. i don't understand how updates are related to the "uploaded by".
anyway, this latter thing is determined by the template itself.
by customizing the tepmlate, you can remove it.
the way i suggest to do this, is to go to the root/home element of the virtual file system, properties, diff template, and put this code
[upload-success]
<li><a href='%item-url%'>%item-name%</a>: <b>{.!OK.}</b> --- %item-size% ({.!Speed.} %speed% KB/s)
this will fit if you are currently using the default template.