i was wondering...
 

how many skill points can you put in a skill?

Depends on the skill.


Some skill parameters for some skills you can't change, like Power for Heal, or effect time for Bash. You can put maximum 5 points into any one facet of a skill (Power/ Effect Time/ Sp consumtion/ Cooldown) and potentially invest in more than one 'facet' if you so desire.

I think you can decrease SP consumption for all skills, as well as cool-time but that doesn't mean you would want to.


edit:-for example, a Fighter's Devastate is one of their best skills. It isn't unusual to see Fighter's maxing all their skill-points in it, putting 5 into cool-time, damage, Sp consumption and effect-time.