Lvl up with a 5 gap will get you around 15k SP
plan on getting to lvl 32. so atleast you get to use the 5th degree weapon.
get Spear Mastery to 31
--put 1 into soul spear
--put 1 into ghost spear
--put 1 into the flying dragon thing
--get the passive to 3
since you plan on staying around lvl 32. and since you should have enough skill points to get all three elemental forces.
get cold to 30
--put one into the cold nuke
--get the passive
get light to 32
--get the must piercing series
--get grass walk
--the lightning nuke
--the passive
get fire to 32
--get the fire nuke
--get the passive
Then get which imbune u want. fire would be the strongest but if you want lightning go for it.
With this, atleast you should have plenty of moves, nukes to have fun with at lvl 32. You will have a very limited PVP range, because most people 30+ will be able to kill you, leaving you only lvls 20-30 to kill

.
Plus if you ever need money, at lvl 32 just go nuke some scorpians and collect Wind 2 elements
What i got listed above with fire imbune came to a total of roughly 9,000 skill points. Therefore if thats exactly what you want, you can probably do a 4 gap. Hope this helps.