What spells are worth / not worth upgrading?

I'm currently pushing towards Champion League, and Im noticing that I need to use at least 3-4 spells every attack, if not all 5. I'm encountering a lot of 3x max Xbow, 2x max inferno bases. My typical army is 2 golems, 3 pekka, 6 giants, 47 archers, and then I use a lvl 5 lightning spell on CC troops, and then I will typically have 1 heal spell & 3 rage spells at the ready. First, is my spell combo "good"? 2nd, all spells are 1 lvl below max. Are any of the ones I use worth the elixir to get it to max level? Also, I rarely ever use the freeze spell, but I hear more & more that it helps negate inferno towers. Do people find that it's sufficient at lvl 1? Is it really worth 12 million elixir to max?