About rabbi millers teshuva, I have seen it and have seen the response from Rav Tavgar. Likewise, I have seen most of the literature on techeiles, so I am not hearing any chidushim here.
About “Reb Chaim”, I have no idea why that sevara is accredited to him being that it is not written anywhere from him, and is not a mistaber sevra at all.
The gemara in Rosh Hashana is poshut telling us in the maskana of the gemara that safek deoraysa will be mechayev you to go somewhere which is a safek if you will be mekayem a mitzvah, even at teh cost of a vadai drabanan. And see the way the Mishna berura explains it in siman 595. About the ran, there is a lot to sasy about Rabbi Miller’s tayneh, but being that all the other mareh mekomos are clearly applicable I will not elaborate.
Once again please see the above mareh mekomos.
About what you said about the lashon gufo, and you are assuming it must mean the outer layer, then maybe ein hachi nami it could have used the word nartiko. To me, this point is not the sslightest nit shver.