First, we are not living under Moses and the Old Covenant. Secondly, both examples you give from the NT have to do with modesty vs. immodesty. The gold and braided hair in the quote from Timothy is about gold braided into the hair…the style of high class Roman courtesans…aka, prostitutes. Paul was counseling women to not flaunt themselves as sexual objects, not flaunt their wealth and status, hence pearls, the most costly jewel of the day. These are closer to core issues of human self worth and identity, and bringing disrepute upon the church in that culture…something that is all over 1 Corinthians in different guises.
What does this have to do with casual or business dress to church? In fact, someone wearing a Calvin Klein suit is flaunting affluence much more so than someone in a regular pair of jeans. What does it have to do with riding a horse or a bike on sabbath?
What are the core issues of Christian life and identity, especially as outlined in the NT? What would you thus see as more ancillary issues in light of this…or do you even think there are any ancillary issues? One example: Does the NT talk more about the food we put in our mouths, or more about giving food to those who are hungry and without? What should pastors be emphasizing more to their congregations, the clothes they wear, or clothing the naked?