I will take none of them does not quite fit. Here is what she would need to say to have the second fit: She had many suggestions, but I will take none of them. In this case, the third choice will also work. The first would not fit this as well. The difference between many suggestions and 'suggested a lot' is suggested a lot is like a single pile of suggestions. How much? A (singular) lot. That means "them" does not fit. Suggestions is plural. "it" does not fit plural. Have fun with that...

Yes

Yes, i think!

Context: She suggested a lot, but .....