I just quit a job and they asked me to sign similar things as I quit. I think I'll just not sign it

In chinese the paragraph is:
乙方同意於離職之日起兩年內,非經甲方事前書面同意,不得為下列行為:
(1) 以自己或借用他人名義經營或投資與甲方同種類相互競爭之事業。
(2) 兼職、任職於前項與甲方相互競爭之事業,其居間或媒介者亦同。
In English that would be (what I think):
Worker agrees within two years from the date of departure, unless authorized in writing by the company to consent to the following:
(1) not by himself or by helping others to have operations in the same kind of business or competing with the companies business
(2) not to do part-time work that is competing with the companies activities, or doing work that is similar to the companies business
They have other paragraph about trade secrets and so on which (what I think) would be already covered by general law.
So why should I bother signing it as I just quit?! Basically I offered them to compensate me for above if they need it, whereas they suggested to strike above paragraphs in that case!
There was no such stuff in my original contract.
Well I still don't see the point of signing the rest. Suppose handing in a notice and giving them back their stuff is enough (legally) when you leave a job?!
I even got a survey with a lot of questions (starting with easy stuff like "how did you like it here and so on" but then some questions like "who is your next employer, whats his name and address, who are his customers" seemed a bit too much to me so I kind of left that one blank too!