Re: #question - How can I mark messages and replies as one's I've already read?
You can do that on the web, sort of.
Where it is Messages / Topics change it to
Messages / Messages ; which changes the button label from Topics to Single :
this presents all the messages seperately one after the other. And each message that you have visited will be a slightly different colour.
On my browser the Unread messages are blue and the Read are gray. This colouration seems to be sticky in this view .
The Messages view sometimes reverts to Topics view on re-opening, so just re-select (single)Messages.
Let me know if you want pictures.