In my opinion: If you have to use ignite, it just says you deal too less damage.
The other thing is, with heal oyu restore HP, and holding longer in fight adds some time to use skills again. And using any skill just 1 time deals much more damage than ignite.
Heal gives me so much kills and saved me endless times. Think of it.

Flash is used for ninja escape or for following an enemy who escaped in the last moment, or flashing through a wall for not losing a kill.

Tipp: Use heal in the last moments for not scaring your enemy away and get the kill!

The Part of Akalie´s GamePlay is to deal damage. The other reason is her passive,
more damage increase her damage again AND her vampiric skills.
1 point goes for defensive, its just for the "Heal" ability.

Magic penetration is the same as ability power increase. The difference between them is,
that penetration "adds" magic damage in % (percent) and not in numbers. Adding damage is percents is more effective than in numbers.

My Itembuild is based on Mastery, Runes and the passive skill of Akali.
1) Magic Vampire (Hextech and ancient) boosts your vampiric up to 53%
2) Magic Penetration (Boots & Abyssal) -20 is more effective than 40% of enemy armor.
by the way it increases your reistance too, and decrease all enemies resist near you.
3) Ability Power, this is the main thing, and rabadons is a MUST BE, it increases your power by 30%.
4) Wraith of Lich, increase your movement speed and power ups your basic attack every 2 seconds. perfect use with akalis spells.

These items in combination with mastery and runes make much targets getting a "snack"

i sometomes do a kill without that i noticed it.

Yes of course it is. You can fight vs more targets at same time as solo. That lifesteal refills your life instantly. In combination with penetration you deal much more damage, and this increase your lifesteal even more.

This gameplay is middle saved. You deal normal damage at beginning. Extra gold until you buy the expensive items would save some time. Hearth of gold is a nice item wich will save your life some times or spends a kill. But u have to sell Heart and Kages later, sell Kages first then!. After you have received Hextech and ancients, it would be much more easy for you.
You boots must be rdy when u have reched lvl 6. Then get ready for gank the whole map.

It is simple.
First farm solo toplane or (would be the best) midlane. After you reached level 6,
you always have to gank after you portet back, so the enemy wont be prepare.
After 2 succesfull ganks u can do what u want the whole time.

Just play as a ninja. be there where you have to be, and never be there, where your enemies are looking at.

Finaly u will see that 90% of your games end with psoitive stats, i got atm 11 out of 12 with positive.

You can use that combination for everything.

Get the blue buff for endless energy and fast skill use, ur ganks cant be stopped then.
Dont be scared of tower dive, u can easily get out there.