Does spell vamp and life steal both work if on a champ such as akali, as in I no her abilities work with spell vamp but if u have LS doe it work on them to and on her basic attacks, and if so do they max out at lower levels or do they still stay at the same max % as if you only had one type.
Life steal and spell vamp work on every champion.
Life steal simply works on auto-attack damage.
Spell vamp works on ability damage.
Neither work on on-hit effects unless those on-hit effects otherwise specify (Such as Hydra's AoE applying life-steal). Jax, Kayle, and Cho'Gath are also cheaters that use it on their on-hit effects anyways.
But the important thing is that neither cares about physical or magical damage like AD and AP, life steal and spell vamp only care about weather something is considered an auto-attack or if it's considered an ability.
LS works on auto atks and SV work on abilities. Also if you are asking if the number values work with each other no they shouldn't. Say you build 
you should on have only 20% per auto and you have 
you should have that 15% on her spells.
If you are talking about Akali only, then it's the Q you are probably confused about. Her other abilites are straightforward with how spellvamp goes.
The initial Q damage is spellvamp. When you autoattack the mark to trigger it, the mark trigger damage is spellvamp as well. The autoattack used to trigger the mark uses lifesteal.
