that I should end each of my posts with a disclaimer to read "Newly qualified PPL with little experience"
That is unbelievably arrogant. You should tell him to p1ss off.
Interesting comment about the "rough and tumble" though. This is a very old characteristic of the internet, made possible by anonymity. When "discussion" first appeared, it was in Usenet, which was famous for its "flame wars". But there was an easy solution for Usenet: you added that poster to a killfile, and you never saw their posts again. Sadly this is not possible on web forums, which all thus have a moderator who basically does that job. Also Usenet had no PM mechanism; one used emails.
However I think most posters learnt to ignore the idiots and still got value out of it. If you don't feed the trolls, they go away. This applies here too.