1. You need a point on bumba to unlock lvl 40 xform
2. Freezing shung costs 3 jellys at once. Everyone (usually) keep it at 1. More is a waste.
3. I'm a big fan of maxed RTT but (yes but) if you don't know how and/or when use it, a maxed RTT can burn your mps. So in the beginning I would keep it at one then if you like it you can put more points.
4. From what I've seen a lvl on the low level poison xform can be useful for that strange combo (need explanations from the pro, I don't know how to explain and I never did it D
5. Only 1 Point on ( I forgot the name XD) pyorok (?). It isn't a good skill but it can be still useful. 1 is good enough
6. Hp potion: it can save you in lot lot lot situations and at low levels it heals a godd amount of hp (or so it did o.o)
7. Any of the eruption skills can be useful for distracting and the tiny invi frame (very tiny) I suggest attack slime
8. (lol) Max Hp regen!! Free hp...why not? o.o and at the same time 4 mp is enough (IMO)
Ok so I wrote a lot but I think that someone could still add something else, maybe all I wrote is wrong .-.