Comlink: Let’s just clarify some things.
Some bring down Al Pi Kaballah not to put hands behind one’s back. It’s clearly Muttar Al Pi Nigleh (see the Tzitz Eliezer’s Tshuvah about putting hands behind one’s back during Shmoneh Esrei).
I have been searching for years and never found a Makor about the feet towards the door thing. Anyone care to help me out? Maybe PAA?
The cutting nails on Thursday thing is a Chumra in several Achronim as a lack of Kavod Shabbos/quasi-Chillul Shabbos issue. It’s certainly a minority opinion, but many are still Mapkid on it. Sort of. (The Mishnah Brurah brings down that the Kabbalistic Ayin Hara of cutting both feet and hands on one day trumps this so one should cut their toenails on Thursday and fingernails on Friday or vice versa.)
I have never heard the fastening buttons in order thing.
2qwerty: Putting on multiple garments at once is Kasheh L’shich’cha. Taking them off is not.