How did your feelings about the Giver change as you read the story from beginning to end?

How your feelings would change about the Giver from beginning to end would depend on how you viewed the Giver at both times. While it is up to you to decide how to feel about him, it might help to look at how the Giver changed throughout the story.

When we first meet him in Ch. 10 and up through about Ch. 18, the Giver seems resigned to his position in the community and what it requires of him. He does not feel he has any power to change anything and perhaps is not even looking to do so:

"I have great honor. So will you. But you will find that that is not the same as power" (Ch. 11).

He also seems resigned to Jonas's taking over of his position. In many ways, the Giver is condoning Sameness, even though he understands all of it pitfalls. In the earlier chapters, when Jonas questions Sameness after only a few memories, the Giver is quick to point out that if people were allowed to make their own choices, they may make the wrong ones. So, although he has the memories and the wisdom of the world, he is still helping to support and contribute to this community of Sameness. 

Later in the book, though, he begins to change. As he sees Jonas question more and more about the community, the Giver is forced to help explain some of the reasoning behind the community's very strange and difficult decisions. When the topic of release comes up, the Giver seems to nudge Jonas into watching the video of his father releasing the newborn twin. He wants Jonas to fully understand the community he is living in, and yet, this is the straw that breaks the camel's back for Jonas. He decides then and there he cannot return home or live with his family anymore. It is in this moment, too, that the Giver begins to realize that he can be an agent of change rather than sit by and be complacent. 

"Having you here with me over the past year has made me realize that things must change. For years I've felt that they should, but it seemed so hopeless. Now for the first time I think there might be a way" (Ch. 20).

The Giver now feels like he has the power to help the community change.

Because the Giver changes so much from the beginning of the book to the end of the book, you could make an argument that your own feelings about him change as well. Perhaps you admire him more, respect him more, like him more, etc... Ideally, we want to see a dynamic character in a novel, one who experiences some sort of change, and the Giver does just that.