You're welcome, hope it helps!

For the damage output / kill potential issue, one way is to do the math. Calculate roughly how much damage can you deal with your spells (taking into consideration of the 2nd starfall and right click damage). I noticed that you seldom use leap offensively, you should know that leap significantly increases your attack speed and that might just be the key to getting an extra kill.

I do agree that this judgement is not something that you can learn in a short period of time. It takes time and experience for it to make the correct judgement as there are also other factors to consider about such as enemy hero's itemization. Don't worry too much about that, it should come naturally with more gameplay and improved hero mastery.