Burnt BD of first project - well worth the effort, results look stunning on main TV.

Summing up issues and work arounds:

Choppy video during pans solved by matching bit rate in profile to bitrate quoted in video file properties.

Freeze frames avoided by chopping whole project into smaller chunks, producing each chunk and then restricting rendered chunks in new project window. This work around is still a bit of a lottery, and in my view shouldn't really have to be necessary - but seems to be until I upgrade my system.

Have confidence in burning BD within PD 10 once files to be burnt have been produced, ie rendered. The disc burning procedure works better than the PowerProduce burn I tried earlier which although successful proved to contain choppy video again.

Many thanks to all here who have chipped in and helped out one way or another over the last ten days or so. Much appreciated. The meek shall inherit the earth, if that's ok with everyone else....