Hi…
Firstly when dealing with footage from SP you need to specify to combustion what the field order is… so you expand your layer select footage and in the source menu there is a field order option. For PAL Sp, set the field order to upper first.
As for cleaning the edges, this actually takes a bit of practice on your part. You need to use the softness and tolerance values plus the histogram to achieve a clean key.. any colour spill can be supressed using the colour suppression menu within the keyer…..
Splice…