1. we don't say the sentence in this way. The answer is more like 再问，but you have to change the "?" to “。” . The translation of this sentence is: I can't believe what i have heard, so I ask him/her again.
2. Both way are correct. “我吃得更多” means I ate more than you. "我吃得太多“ means I ate too much.
3. All of them are correct. "中国人不像西方人” means Chinese don't look like western people.
"中国人不如西方人“ means Chinese are not good as western people. "中国人不懂西方人” means Chinese don't understand western people.
4. 说 and 讲 are correct. if you use 告诉， there must be an object after it, like 告诉他，告诉她 or 告诉百瑞格。
5. 也 and 都 are correct. .......difficult to explain why can't use 还。
6. “觉得” is correct. tanslation: they haven't recognize(觉得） anything wrong. it is like something
bad or wrond is happening, you can feel it or recognize it, but you can't think it or believe it. (hope you can understand........)
(sorry for my poor gramma)