Hi.
Depends what is your goal and what you final delivery needs.
You can edit in HD if your system is up to it and later scale down
as PAL anamorphic or just PAL fitted in with to 720*576 from hd.
This gives you option to output final program as HD also if needed.
If you go and scale down to SD before edit it would be much harder to make HD edit on SD material.
More like question of taste.
Generally pal is 25 frames per second or 50i. 25 full frames gives you bit more movie look.
—
Margus
https://iconstudios.eu