[Soapy]

Exceptional Arsenal
Worth: 2 TP

Requires: 15 Base Skill
"Why focus on one thing, when you can focus on everything?" - You. Increases available Skill Slots by 1.

More to come, at least one of which is based on a new suggestion coming to a thread near you soon™.

[Grandpa]

please and thank you

[Soapy]

Polymath
Worth: 1 TP

Requires: 10 Base Strength, 10 Base Will, 10 Base Skill
A man truly can do all things if he will. Increases your cap on total SP by 20, but reduces the maximum amount of SP usable in all promoted classes by 10.

Master of (Magic/Archery/etc)
Worth: 1 TP

Requires: 20 Base (Will/Skill/etc), (Arcanic Study/Marksman/etc)
Gives your (Mage/Archer/etc) and any (Mage/Archer/etc) promoted class 4 Skill Points, but reduces your cap on total SP by 10.

(One for each base class.)

For context on these two, check out another thread.

[Trexmaster]

The only issue I have is that the +SP trait is infinitely superior to the +SP cap trait in the long run (assuming the SP cap is sufficient enough to put points into two promos).

Otherwise, the trait in the OP sounds fine.

[Ranylyn]

This has my support.