The wiki says that resistance is more like this:
4 BB = 60% chance to resist = 40% chances to be hit.
A spell that has 140% chances to hit has, with 4 BB taken into account, only 40% * 140%, which is 56% to hit. In other words, BB provides here 44% resist.
Your post is hella confusing because you don't say what comes from tooltips, and what comes from your own assumptions/formulaes, which could be erroneous.
Skill 140% -> 45% to resist, 82% due to BB=4
Makes the full resist to 85% with BB=4, it should be 60% (+25%)
In bold what seems to make sense (44% close to 45%), the rest I have no idea.
BB4, Skill 120% -> 53% ?
YES, because 60% resist/40%hit, so 120% * 40% = 48% hit/52%resist
WP=2, Skill 135% -> 6% ?
YES, because 30% resist/70%hit, so 135% * 70% = 94.5%
BB=2, Skill 145% -> 2%
?? NO ? Same example as below.
BB=2, Skill 145% -> -1%
YES, because 30% resist/70%hit, so 135% * 70% = 101.5%
BB=4, Skill 140% -> 45%
YES, because 60% resist/40%hit, so 140% * 40% = 56%