<<So there is no cap to actions?

There's no hard cap on Wildfire that says "no more than x weaponskills," but there's a soft cap determined by the duration of Wildfire vs the GCD of your weaponskills which effectively means there's a limit which could theoretically change if your GCD sped up a lot or the duration of Wildfire was increased. Note that this has to be weaponskills specifically, not abilities so not everything triggers it. If it calls it a weaponskill in the tooltip then it works, and if it calls it something else like an ability then it doesn't.