Expectation - Should have or not to have?

Should we have expectations of one another and of God?
Let's first look at the bible
Job 29:21
"Men listened to me expectantly, waiting in silence for my counsel.
Psalm 5:3
In the morning, O LORD, you hear my voice; in the morning I lay my requests before you and wait in expectation.
Romans 8:19
The creation waits in eager expectation for the sons of God to be revealed.
Hebrews 10:27
but only a fearful expectation of judgment and of raging fire that will consume the enemies of God.

Luke 6:34-35
And if you lend to those from whom you expect repayment, what credit is that to you? Even 'sinners' lend to 'sinners,' expecting to be repaid in full. But love your enemies, do good to them, and lend to them without expecting to get anything back. Then your reward will be great, and you will be sons of the Most High, because he is kind to the ungrateful and wicked.

Think it should be quite obvious from the verses that we should come to God in expectation. But will our expectations all come to pass? i would say no. Well, then why run the risk of having to feel disappointed? while it may really be true that without the expectation, we'll probably not feel upset, but it is not right to not expect; not anticipate things to happen just to avoid the agony that it might not be attained at the end.
I believe sometimes it really is not about stop expecting as a whole, but to think whether that expectation is what God wants us to be expecting. if we are expecting something that God doesn't want us to have at this moment, of course you will have to face disappointment at the end. God didn't give us the emotion of disappointment to torment us, but to challenge us whether we still trust that God has kept the best for you even when you do not get what you want. It is growing your security in God.
The verse in Luke talks about showing love without expecting anything in return. This does not contradict with anything mentioned above. We do good not to make sure we receive it back, that simply is not love at all. It isn't an issue about expectation at all.
Finally, just want to end by drawing our attention to God and how he demonstrates this. When God created man, He gave them freewill, expecting that they will obey His instructions and not eat the forbidden fruit. If God didn't have this expectation, He wouldn't be angry when they disobeyed. But God did not from there stopped loving man. Though we receive punishment, but God still meticulously watches over us. Moreover, do you not know, God is omniscient and omnipresent. This means that God knows that man is going to disobey and He is going to be upset, but He still expected. And He did so because He loves us.