Ubiquitin,
1. Not at all. Their yichus in unclear. The Ridbaz (Responsa, 4:219) accepted one of their number as a Jew but that was almost five hundred years ago. Since then there is no way of knowing whether or not they intermarried.
2. I thought that that was obvious from my statement “I do not know if anyone has even asked before you.” IMHO it would not be better to ask a clear-cut gentile to be on the safe side. However, if you are in Israel or plan to come and have a burning desire to have such a problem on Shabbat and davka ask one of them you should ask your LOR as I posted.