Are the tatics u get from leveling points spent in the Career trees always active or are they just like the other tatics you can get from Renoun and you can only use 1 at a time?

I would hope the ones in the career trees are always active?

No, the tactics do not change. What does change are the amount of slots you get. 1, 2, 3, 4 for your levels 10, 20, 30, 40. You get 2 reknown slots, I am not sure when you get the second one. You always have 1 tome slot.

The only passives you get are the ones that you get from the reknown trainer (your skill passives are separate ie what types of weapon you use) that adds to your abilities - strength, armor, crit, etc.