Well, I suppose I'll share my opinion as well.
Rachel Berry and Kurt Hummel are actually my favorite characters on this show. Followed by Santana and Mercedes.
That being said, when I first started watching the show, I hated Rachel. I thought she was the most annoying, obnoxious, self-absorbed character ever written in history who only think about becoming a star. But, my gosh, she could sing. Then along came Finn and suddenly she was thinking about more than just being a star. She had someone she liked and she was just like an elementary student who had their first crush. It made her a bit more relate-able. Also, let's face it, Quinn was kind of a b**** in the beginning and at different moments throughout the show. Rachel thought Finn deserved better and she liked him and so, she did some questionable things about that. But, before I realized it, I was rooting for her to get the guy she liked which was odd since I thought I couldn't stand her. Then in certain episodes, she'd have a breakthrough with different characters. Eventually she became friends with Kurt and Mercedes and a few others. Then I finally realized that I really liked Rachel. She'd grown on me. So, I tried to figure out why I liked her and I eventually realized.
When the show starts off, look at where Rachel is at in her life. She's been working towards Broadway since she was two and she has two dads who have taught her all her life that she is a star, will be a star, and that she's better than everyone else because she is a star. Her dads never taught her how to get along with others, they only taught her that she was talented and amazing. So, when she joins Glee club, it's like watching a toddler begin to interact with people for the first time. Only, these people already know how to interact with others. So, throughout the show, you watch Rachel as she learns that there are other things in life besides me extremely talented. She learns that the world doesn't just revolve around her. She begins to care for these people in her club and she's clumsy about it, but she slowly gets better. Such as when they had their neglected artists week. She told Mercedes that if she wanted the last spot, she should take it from her. And when Mercedes finished her performance, Rachel told her that she couldn't follow it.
She was there for Kurt when his father died. She helped bring Quinn back to Glee. Eventually she, Kurt, and Mercedes become a trio and their friendship just made me so happy. Rachel's song that she wrote herself about how much she cared and the fact that she was bad at showing it because she's clumsy at it. When Rachel and Kurt had breakfast at Tiffany's, and when they sang on the Broadway stage together. Rachel quit running for presidency when she realized Kurt was better suited and then tried to foolishly help him win and confessed the truth when he almost got in trouble for it. There are so many moments in the show where Rachel proves that she's learning to care about others and she's such a better person that she was in the beginning. Regarding Finn's dreams, Rachel actually decided eventually, that when Finn found his dream, they could follow it instead of hers. She WAS willing to give up a dream she'd had since she was two to make the guy she was in love with happy. Even though he said from the beginning that he was happy to let her follow her dream.
Also, I don't think Rachel was trying to sabotage Kurt for his performance. She believed that doing a song he knew through and through was better as she believed it was for herself. But, then he took a risk and it paid off. And she was happy for him, but she'd heard what the woman said to Kurt and that made her worried for herself. But, her brain told her to stick with what she knew so she did. Personally, I think she choked because while her brain was telling her one thing, I think her heart was telling her to take a risk. So, she couldn't sing the song. The pressure she was putting on herself had a lot to do with it too. But, throughout the series, she's usually done her best when she's taken a risk. So, I think she realized that she shouldn't have been so worried about giving a safe audition and should have instead given one that was bold.