what does it mean when you are asked to make for example ask.com your default search engine?

[J]

the site you visited is trying to make money by affiliating with ask.com which is another search engine along with bing, yahoo, aol, baidu, google and others.if they are willing to give you something shouldn't you be willing to allow them to make a little money from your searches? you could always switch back later.

as to using Chrome or for that matter ANY google product, you should do your homework. Chrome and Firefox have backdoors that allows Google to see the ads you click, Gmail another Google product reads your emails for words they can use against you IF you are an IM or use to show you their ads from their DoubleClick division.