Begin bot 
I am bot. I cannot explain nuance. But I can state my algorithm:
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All stones on the board are assumed alive unless players tell me that they agree they are dead.
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Empty intersections connected to stones of one color only are territory of that color.
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Empty intersections connected to stones of both colors are neutral.
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Alive stones touching neutral points are in seki.
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Under Chinese rules, territory surrounded by stones in seki count as points; under Japanese rules, they do not.
End bot
(Note that in the OP, all games are Chinese rules and 5.5 Komi)
Results
Game 1: B+18.5
Game 2: B+35.5
Game 3: W+41.5
Game 4: B+12.5
Game 5: W+6.5
Simple algorithm. No need to judge life and death. No need to judge open borders. Game is scored as it is. Never fails. If players choose to:
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Pass before borders are closed and/or before dame are filled; and
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Also leave without marking dead stones
then that is their free choice but don’t be surprised if the auto-score does not guess where you would have played! (How can it?)
Players must do at least point 2 above (or do point 1 plus capture all dead stones) to ensure auto-score is as they want it automatically.