My uninformed take:
If we're tight on cap it makes no sense to release EJ, he's about as good as any other back up out there, and he's guaranteed I think
Mario I could see being gone, unless he renegotiates. Which probably means we need to draft a stud DE.
I doubt Kyle renegotiates, he's already not being paid that much* for his skill level, even though he's older. (yes I know this is debatable)
Gilmore is signed in 2016, I think.
We need to retain Glenn and Incognito, imo.
Not really sold on Bradham in Rex's system, but if he's cheaper than a potential replacement, we might retain.
McKelvin is good depth, but expensive. I'd attempt to extend/renegotiate at a cheaper price, if not, cut.
Aaron Williams would be a big cap hit if cut, so he sticks around unless he retires.
We'll end up with some money to play with, but we're definitely not going to be big players this year, unless a trade frees up a lot of money. We were 'all in' for this season, and it fell on it's face. It'll be a few more years before we have space to make the moves necessary to be a contender, or until we get new coaches.