Is it acceptable to use sono again before particularmente in this situation.? e.g. Sono Magri e non sono particularmente alti
Yes, it isn't bad Italian at least.
In that case I shall report it as I just got knocked out for doing exactly that :)
In the case of "Sono magre e non particolmete alti.", should "alti" not be "alte" to agree with "magre"?
Yes, you should report it.