Athletcism node for RF build

Should I avoid this one even it is 8% hp boost? With the 5% fire self-burning I feel it is a big enough penalty to myself to take the node. I am not sure if the 5% buf on Purity's max fire resist will do anything at all.

Should I avoid it just like inner force or is there a diff side to the story which I should get it and inner force because it will boost my max resist?

It's not that bad. If you burn for 10% of your health per second without it, you will burn for 10,5% if you take it. Better to avoid it if you can but it shouldn't break your build even if you must go through it.

Usually you boost max fire resist on purity with aura nodes and avoid inner force like plague.