Two tipping scenarios that have been bugging me

[Weir]

1. Mr. Chinese food delivery man. There is no minimum $ order or delivery charge as far as i can tell from the menu. However, I order an $8 dish and it comes and the bill says $11. It is freaking good, so I order it again. It is a different price, something like $12. I don't really mind paying this much, and i don't want to hassle over the price because they really barely speak english. am i required to tip? i haven't and part of me feels bad, but i think paying $15 for random delivery dinner would make me feel worse.

2. Mr. Italian food man. I call in an order and come by and pick it up. I never do this so i don't know protocol. There is a tip line on the receipt, which isn't suprising b/c it is a restaurant, but i don't tip b/c i figure i am the one who delivered it to myself. Correct?