Conversation:

I've tried to link to a forum conversation before e.g.
F19585?thread=?thread=331048, but can i hide this behind a name, like you do when linking to a guide entry or external site?

You can name your links anything you want, as long is they're in an entry - you can't name them in a conversation though...

See directly under header 'Links':

To create a link to an h2g2 page, use this tag:
Your description

You can exchange "name of page" with a link to a conversation