In Romans 14 Paul is addressing our relationships with each other. The whole context of Romans 12-16 is about relationships with others.
Rom. 12:5
"So we, being many, are one body in Christ, and every one members one of another."
12:18 If it be possible, as much as lieth in you, live peaceably with all men.
13:8 Owe no man any thing, but to love one another: for he that loveth another hath fulfilled the law.
Then to start chapter 14 he begins with
"Him that is weak in the faith receive" and
"another, who is weak, eateth herbs".
Paul is not advocating such behaviors as being Law or ordinances for the church. Rather he is admitting that when people are saved they can bring a lot weakness of faith to this new salvation. Since we are a body, we are to function with each other out of love. He is telling people to get along with one another and grow in faith together. We are not to break fellowship with others just because they are vegetarians or vice versa.
"But why dost thou judge thy brother? or why dost thou set at nought thy brother?
10)
Rather than focusing on what we disagree on he is telling us to look at what we have in common.
:19 "Let us therefore follow after the things which make for peace, and things wherewith one may edify another." This is telling both sides on the issues here in Rome that they are wrong and need to not push their agenda.
How are we to "practice" these differences? :22 "have it to thyself before God."
This is where the Galations were running into problems. Some were not keeping these things to themselves "before God". We know this was happening in Phillipi, Colosse, Ephesus, and Crete. It is probably safe to say that it probably happens wherever the gospel is preached.
Paul looked very differently at those who were practicing these carnal commandments than he did at those who were preaching it. Those preaching
"touch not, taste not handle not" (Col 2) were said to be taking people back into bondage to the rudiments of the world and removing them from Christ.
To use Romans 14 in a defense of carnal commands exhibits a lack of understanding regarding the kingdom of God.