Your question on Rashi (who says "at the time of Lechem Hapanim there was no 2 day Yomtov, as if there now is such a thing in Jerusalem) is wonderful! In fact, the TZELACH (written by Rav Yechezkel Landau, author of the Noda Beyehudah) to Pesachim ad loc. is bothered by it and offers not a hint of an answer.

1. Your answer is likewise both original and satisfying -- he may mean that even if there were no Israeli Kohanim around, they still wouldn't have to push off baking the Lechem Hapanim for two days. You hit upon the explanation of Rav Yosef Shaul Natansohn (in his footnote to the Chacham Tzvi siman #167)

2. Alternatively, I may point out that some Tanaim hold one may bake the Lechem HaPanim out of the Mikdash (Menachot 85b). If so, Rashi may mean that even if no furnaces were available in Israel, there still would not have been a two day delay.

3. The CHATAM SOFER (Yoreh De'ah 252, Chidushim on Pesachim) says that in his youth he passed by the Nodah Beyehudah's town, and built up the courage to suggest to him an answer to this question. He pointed out that in Berachot 63a we are told that when the greatest Talmid Chacham in the world lives in Chutz L'aretz, he may make a leap-month without the permission of the Bnai Eretz Yisrael. The Chatam Sofer contends that this is only when there is no Beis HaMikdash.

If so, Rashi here means to say that when there is Lechem HaPanim (i.e., a Beit Hamikdash), there is no two day Yomtov in Jerusalem -- but otherwise, there may well be one! (The wording of Rashi, "Yomim Tovim shel Goliot, doesn't fit in so well according to this Peshat, as is pointed out by Rav Yosef Shaul Natansohn in his Hagahoh to Chacham Tzvi, siman #167).

4. MY SUGGESTION, however, is that the question doesn't really start! You must have noticed that it is strange for Rashi to refer to "Zeman Lechem Hapanim" when he means "Zeman HaMikdash". I think that the word Zeman doesn't mean "the epoch of," but "the times for bringing" the Lechem HaPanim -- which is exactly what the Mishnah is discussing (9-11 days). Rashi means that unlike the Mishnah that discusses Milah (Shabbos 137a), which mentions 2 days of Rosh Hashanah but means any two day holiday, this Mishnah *does* mean specifically 2 days of Rosh Hashanah. Why? Because Lechem Hapanim is made in Jerusalem only, of course!

To make this even clearer, Rashi must hold that by Milah R.H. *is* the only thing that pushes off Milah for two days, like the Rambam holds (Hil. Milah 1:15, see Kesef Mishnah). He was bothered, in Pesachim, by this, because if so we can say that only R.H. pushes off Lechem HaPanim two days, but not another YomTov -- which would run contrary to what the Gemara is trying to prove in Pesachim, that on *any* YomTov cannot prepare food for Shabbos. Therefore he had to point out why here it only mentions R.H. and not other Yomim Tovim!

By the way, the Chasam Sofer is Gores in Rashi "Lo Mashkachas Shenei Yomim Tovim...", not "Lo Hayu...", which fits in even better.

Let me know what you think of this -- and keep those questions coming! We've started Chulin in Kollel D.A.F., and we'll need friends like you to keep us going, BE"H! Hopefully, by the time you get to Chullin I'll have a week's worth of stuff up for you to browse through.

Be well,

-Mordecai