[Avodah] changing paradigms?

[Rich, Joel]

The more I learn Shulchan Aruch and Mishna Brurah the more I understand
the Maharshal's opposition to codification vs. relearning the basic
sources to obtain the clearest understanding possible of Chazal's
underlying theories for extrapolation to new cases (each iteration away
from the primary source can cloud fine points, or Godel's incompleteness
theorem at play?).

I also see much more of the implicit sociological assumptions made
over time (and wonder how we define the community [e.g., town, city,
continent...] and time [every decade, exile...] that we measure). Two
examples:

1) S"A O"C 153:12 (MB:76) discusses an individual who had a stipulation
with a community to build a Beit Knesset (synagogue), it stays with him and
his family but it's not transferable. Why not? "Mistavra" (it's logical)
that that's what the community had in mind unless specifically stipulated
differently at origination (me -- who measured? How?)

2) S"A O"C 153:18 (MB:95) concerning a private object (e.g., Menorah)
used by the synagogue. Originally, the assumption was they became kodesh
once used, however, "now" it's assumed that they remain totally private
(as if this were the original stipulation). So how, when, and where
did this change? Were the first people who acted this way sinners,
but enough sinners makes it OK?

KT
Joel Rich