Skill Coooldown Reduction Potential

Does skill cooldown reduction potential stack and am I allowed to make my neither shield cooldown of 6 seconds go to zero with 2 lines of this in potential and 2 in bonus potential?

Im certain that there is a cap of -5 seconds from potential sources, in fact if i recall right its even on the cooldown reduction potential description. Im not sure if Mercedes card allows to go past those 5 seconds but i dont think so as the card description also mentions that the max it can reduce is 5 seconds.

The merc card description is misleading. It can reduce CD by more than 5s, but it can't reduce a skill's CD to below 5s.

also, I'm pretty sure the least cd you can have on a skill w/ CD is 5s, unless you count those skills w/ -100% CDR hypers and stuff.

The merc card description is misleading. It can reduce CD by more than 5s, but it can't reduce a skill's CD to below 5s.

also, I'm pretty sure the least cd you can have on a skill w/ CD is 5s, unless you count those skills w/ -100% CDR hypers and stuff.

This is not the case. With any cooldown reduction potential, there is no minimum cap (you can go below 5 second CD). The Mercedes character card also takes 5% of the full cooldown, capped at 5 seconds of reduction for skills with 100+ seconds of initial cooldown. The Mercedes cooldown and the potential cooldown reductions stack and their caps remain separate.

OT: The lowest a 6-second skill can go would be .7 seconds theoretically, which is close enough to the delay for almost no-cooldown. If you know how potential works, you won't even try to attempt 4+ seconds of reduction.