Hey Cutereems,
Well jsut to fill you in a little, they haven't really shown Mishti really hating Kripa, but when she comes to now about Angad and Kripa, then she definitely gets mad at Kripa. While playing Volleyball she intentionally hits the ball right at Kripa. She now thinks that Kripa is in competition with her.
Also, she is mad at Naina for telling her to be close to Angad, when she knew that Angad did not love her and loves Kripa. Mishti tells Naina that she won't let Naina do anything to hurt her and she will get Angad anyhow.
I don't think Angad will marry Mishti, but Mishti sure wants to marry him. We will see that Mishti will soon paying 50 crores to save Angad and then he will be indebted to her. Apparently, till now they haven't made Mishti look like a bad character, but soon I think she will do anything to get Angad.
If you have any more questions, I'll be happy to answer them. I hope that I cleared some doubts that you had. Let us know if something is still unclear.
-Love4ever!