VM;
1) As I previously mentioned, it depends on how the dishwasher works. If the soap is released after the hot water with treif food floating in it touched the dishes, it treifs up the dishes. I was told this regarding home dishwashers.
2) Correct, I was illustrating, by example, that it’s likely to be switched. It wasn’t a raya. Understand, though, that the normal rule of “achzukei issur lo mechzkinan” (we don’t assume issur) was suspended for milk (the gezeirah of cholov aku”m), so once the seal is broken, and the milk is unsupervised, it no longer has the status of cholov Yisroel.
2a) That is incorrect. Many poskim do not hold of the heterim of R’ Moshe, the Pri Chodosh, etc. According to these poskim, unsupervised (by a Yid) milk is completely assur (mid’rabbanon). Many people follow these shittos.
There is also an opinion among some rabbonim (the Nirbater Rov is on record, and I spoke to a prominent Litvishe posek who concurs) that R’ Moshe’s heter no longer applies because of some technicalities in the way the distribution of milk has changed. Rav Belsky disagrees, and I’ve heard that R’ Dovid Feinstein holds that his father’s heter still applies.
The point I’m making is that there are a couple of legitimate halachic angles to say that unsupervised milk in America today is absolutely assur, so it’s not semantics to differentiate between keeping C.Y. as din or chumra (I personally keep it as chumra, but since I’ve heard that the modern applicability of the heter is questioned, I am more machmir than previously).