Please check my sentences

[hirashin]

Dear native English speakers.
Would you please check my sentences? Would all of them be used?
(1a) I went to the U.S. last month.
(1b) I visited the U.S. last month.
(2a) My uncle has been in China since last month. (I believe that "to" instead of "in" can't be used. Am I right?)
(2b) My uncle has staying in China since last month.
(3a) Did you go to London last year? (Would "Were you in London last year" have the same meaning?)
(3b) Did you visit London last year?
(4a) Have you ever been/gone to New York? (I believe that in British English "gone" would be wrong.)
(Do you also say "Have you ever been in New York?" with the same meaning?)
(4b) Have you been/gone to New York before?
(5) I lived in China when I was a child/kid.
(I believe that "I was living in China" would sound strange in this case.)
(6) "Have you had/eaten lunch (yet)?" "No, not yet." (I believe that in American English, "Did you eat lunch yet?" would be used.)
(7a) I have lived in Canada since I was eight.
(7b) I have been living in Canada since I was eight.
(8) I lived in Canada when/while I was eight to twelve.

I'd appreciate it if you could check any of my sentences and give some information about them.

Hirashin

 

[OoTmaster]

1(a) and (b) are used. 2(a) yes that's correct "in" can't be used for that sentence. 2(b) I suspect a typo but it should be "has been staying" instead of "has staying". 3(a)Sentence is correct. "Were you in London last year" could mean the whole year. 3(b) Sentence is correct. 4(a) Both are correct at least in American English can't comment on the British part. 4(b)Both are correct. 5. "I was living in China" works best with a "when x" situation is need for example "I was living in China when the new leader came into power." 6. Both are correct. (Yes "Did you eat lunch yet?" is correct for American English. 7(a) and (b) are correct. 8. I understand what you're trying to say but it seems an odd way to say it for me. "I lived in Canada from age eight to twelve" sounds more natural to me.