1) Rashi 2a (d"h MiSho-o SheHaKohanim) - Rashi says that this time is after the kohanim have immersed themselves and the sun has set "and their time has arrived to eat T'rumo". What is this special time that kohanim have to eat T'rumo? Rashi should have said that then they are able to eat T'rumo.
2) Can we assume from the last Tosfos on 2b that Rebbi Y'hudo holds that reading K'rias Sh'ma is MiD'Rabbonon since he does not 'darshin' the posuk of "B'shochb'cho Uvkumecho"?
3) And if so, does the Ri in the first Tosfos on 2a hold likewise when he says that the Sh'ma read in shul before Tzeis HaKochavim is the one through which we fulfill the mitzvo?
M. Perlman
1) Since their ability to eat Terumah is time-dependent, Rashi calls it Higi'a Itam." The two terms are thus identical.
2) Perhaps, see Berachos 21a
3) Perhaps, see Rebbi Akiva Eiger, Berachos 21a, in Gilyon ha'Shas. Excellent point.
Gmar v'Chatimah Tovah - May you have a year of blessing and health!
Kollel Iyun Hadaf