As per Rav Aviner’s shita, one can visit museums on Shabbat outside of Israel. However, most cities do not have eruvin. As such, can I put tickets to museums in my shoes to act as soles so that I may visit some museums?
I can not comment on what you are quoting from R’ Aviner, however regardless of whether you can or can not visit a museum outside Israel, you can not carry the ticket in your shoe on Shabbos. Even though it is possible that the museum is on a street that is only a karmeus, and getting to the museum would only involve going on side streets that are not a reshus horabim, nevertheless we may still not carry even with a shinui in a karmelus.
Even a shvus dshvus when done by a gentile can only be done if there is a big need, but here it is being done by a Jew, and it isn’t considered a big need.
Aside from this, it really isn’t in the spirit of Shabbos to be visiting such places, because it takes us out of the ambiance that Shabbos should give us. Therefore besides for the halachic issue, for the sanctity of Shabbos, it should be avoided.
Best Wishes, and you should have a good year.