Hi
As I mentioned....
My advice is to only add subtitles after editing has been completed. As they are not linked to the clips and are time related, editing the timeline will not re-adjust them. Currently there is no way to link them.
If you have edited a section in the video after you have added your subtitles, you can easily (but annoyingly) reset the RED/BLUE IN/OUT markers for each subtitle in turn from the subtitle screen list. This will reset the Start and Stop times to new values.
However, the subtitles preview screen shows the whole timeline sequence not just a single clip beneath the window so you can play through it and check if the subtitles positions require correction. Each subtitle (position and duration) as it is reached during playback is shown on the thumbnail line as the highlighted area between the red/blue marker bracketss. Just drag these right or left to move or change the subtitle duration or position. If required re-save the SSA file.
Nat