Things you can say to show will grant a request, but that you're not happy about it.
 

Scenario 1
A thug tells you to give them all your money or they'll hurt you.
What could you say in Japanese to show that you'll comply with their request? Would any of these sound natural for such a situation?　
いいよ　(ii yo) - Fine.
いいだろう。　Fine.
大丈夫　(daijoubu) Okay.
はい　　(hai) Yes.
するよ！　(suru yo) I'll do it!


Scenario 2
A co-worker (not your boss) asks you to do something. You don't want to do it, but you give in anyway. What would you say to show that you're not happy about it? Would it really just be a matter of your tone of voice and body language? Would the below sound natural?
いいよ　(ii yo) - Fine.
いいだろう。　Fine.
大丈夫　(daijoubu) Okay.
はい　　(hai) Yes.
するよ！　(suru yo) I'll do it.

Thanks!

Let me explain what the listener think when each replies are made.

Scenario 1
いいよ　(ii yo) - Fine. : why he is so friendly?
いいだろう。　Fine. : He is not afraid of me
大丈夫　(daijoubu) Okay. ??? Does he agree with me or not?
はい　　(hai) Yes. : He is soooo tame.
するよ！　(suru yo) I'll do it! Why he is so happy?
(I think usually Japanese will say nothing in this case)

Scenario 2
いいよ　(ii yo) - Fine. : He is a good guy.
いいだろう。　Fine. : He is so arrogant
大丈夫　(daijoubu) Okay. Does he agree with me? or ignore me? I must ask again.
はい　　(hai) Yes. : He is too tame.
するよ！　(suru yo) I'll do it! : OK, he is happy t do it.
今回だけな （KON'KAI DAKE NA：Only This time(never do it again)) : hmmm.

Thank you! That was a helpful way to answer!