1) If I ate meat, within six hours can I toast a piece of bread in a dairy toaster if the rack may have milchig residue?
Please provide sources
If the bread was put directly on to the milchig residue, then you would not be able to eat it, until after the 6 hours are up as the milchigs is absorbed directly into the bread. However if it isn’t directly on it then it would be permitted, because we are not going to assume that there is zeah from the dried out residue in the oven.
As a side point, in a similar instance, to cook in a milchig pot that has residue left in it, then the halacha would be different. If the residue in the pot is less than a 60th of the bread, and botil to the bread then it is permitted, however if it is more than it shouldn’t be eaten. The reason is that if the amount of residue that is absorbed in the bread would give “taam” then it would be considered like dairy dish, which may not be eaten within 6 hours of eating meat, however if it is less than a 60th then it isn’t considered a dairy dish.
Y:D 105-4, Yad Yehudah Y:D 108- 21 (kotzer), Igros Moshe Y:D 1-40, Atzei Haolah 3-19 brought in Hadar Hashulchan 8-4, this is also the ruling of R’ Y. Belski zt”l (Piskei Halachos pg. 135). The ruling of the Shach that one may eat dairy after eating a dish cooked in a dirty meat pot will not apply here, since in the case of the Shach the person didn’t become fleishig in the first place, however here he is already fleishig, and may not eat something considered milchig. See Yad Yehudah (Aruch) 97-6.