These are all Old Covenant regulations. When God established the Old Covenant, He established not just a religion but also a separate nation. **So the regulations encompassed everything needed to regulate a religion and a nation **-- that is, both religious laws (religious ritual laws, moral laws…) and civil laws - which include health regulations, criminal justice laws establishing punishments for breaking laws etc.
People may fuss about all the OT laws, but they all fit in just the first 5 books of the Bible. Think of how many volumes are needed just to contain all the civil laws in force in our nation!
The New Covenant replaced the Old Covenant. It is only the OT eternal moral laws which continue into the New Covenant.
- The New Covenant did not involve establishing a separate secular nation. It was for all nations. Therefore the particular nation one belongs to is responsible for establishing civil laws. Christians are subject to those laws.
- The New Covenant established new religious rites with a new priesthood.
So, to go briefly thru all the issues raised in the letter you gave a link for:
a) OT religious rite replaced by NT rite/s
(BTW, even Jews cannot follow this law since all sacrifice was to take place at the temple and the temple has not been in existence since 70 AD)
b) Civil laws now cover slavery and its legitimacy.
(Just a side note: she could only be sold to her own people - not foreigners. Also other conditions applied. See following verses)
c) As the question reads, it implies sex outside of marriage – which is still forbidden under the moral code, whether menstruating or not!
d) Civil law applies.
(I do not know if the Church has any regulation regarding slavery being forbidden or not. There can be some societies/cultures where it is humane to have it - assuming one treats slaves respectfully.)
e) National criminal justice laws apply,.
d) OT health/food laws (re clean & unclean) no longer apply in NT (Acts 10:9 et seq)
f) OT priestly requirements no longer apply. NT established a new priesthood with new regulations.
g) ?? Not sure basis for OT regulation, but if there was a moral basis at the time, it no longer exists today.
h) See (d)
i) National agricultural laws apply.