SureAI

Hello. Anyone knows if i must save these plants untill i train stats( resp. Strength) to 100 (like in Gothic,Risen) , or 100 is the level cap for those stats and consuming the plants is recommended right as u pick them (this way saving those precious points spent when u level up) ? Thank you.

No, both act as a (permanent) buff.
One directly affects the carry weight. The effect of other can't be seen in the stats, only via console and getav.

The luck raiser has nothing to do with the usual way you raise your luck. You can see it in your stats menu as a bonus. It does not matter whether you consume them immediately or wait until later - the effect doesn't change. So nothing speaks against consuming immediately.

Ice claw boosts your encumbrance limit; it doesn't change your Strength attribute. So, again, no reason to wait.

yes, i realized that now; i was mistaken by the +1 strength description of ice claw