Jothar first off you forgot the Rambam from your list of “mainstream” Poskim as well as the fact the Aruch HaShulchan seems to understand that the Shulchan Aruch learns Lmase that one must get drunk ( Aruch HaShulchan Siman Tuf Reish TZadik Hey Siman Hey.
Regarding Chayei Adom, until the Mishna Berura came out chayei adom was cosidered the “Da’as Achron” the reason the Mishna Berura took its place is because it was more comprehensive as well as the indisputed status of the Chofetz Chaim as the Gadol HaDor.
As to what my Rabbeim held, Exactly what they did , One is required to get Drunk to the point of complete inebriation.
As an interesting aside it is noteworthy that the name of one of the senior Roshei Yeshivos in America is missing from the Kol Korei against drinkig beer, upon ivestigating the matter I was told that he held because in many Yeshivos including when he was a Bochur by Rav Aaron Bochrim drank whisky it was established as a Minhag Yeshivos “Kol Midi D’mishaker” ( in theory I would think the origins is of this would be because of the simple fact that in Europe they did not have wine, just speculating)consequently He did not feel Himself to be of a stature to sign against a minhag.
I questioned a close Chaver of this Rosh Yeshiva (and Odam Gadol in his own right) as to whether it was true and he told me I did not see it as I don;t read the papers and did not ask him but I could’ve told you he would not sign such a staatement The Frediker Gedolim saw many of us drinking whisky on Purim to be mekayim the Mitzva and never said anything he will not open his mouth where hi Rabbeim did’nt.
Again to say that Gedolai Oilam did not hold of getting Drunk is ridiculas to say that other Gedolei Olam did not hold of it is ridiculas as well.
Each person must follow his Mesorah, his rabbeim and again I would highly recommend Rabbi Yossi Rosenbergs article in this weeks Yated to all those who think drinking was never a part of Purim and the act initself is a Chilul Hashem.