Your scoring system is a valiant effort, but probably needs a tweak or two.
For one thing counting Velazquez as a starter there might be wrong. That was arguably a bullpen game.
The other question that arises is how what results would this system produce if you applied it to other teams?
My sense is that bullpens have a fairly large built-in advantage. The starter is one guy, the bullpen is a team of 7-8 guys.