I think the best way to understand Christian Liberty is to go to the Westminster Confession where it is defined. In the first paragraph we get an excellent explanation of what Christian Liberty is:
1. The liberty which Christ hath purchased for believers under the gospel consists in their freedom from the guilt of sin, the condemning wrath of God, the curse of the moral law;a and, in their being delivered from this present evil world, bondage to Satan, and dominion of sin;b from the evil of afflictions, the sting of death, the victory of the grave, and everlasting damnation;c as also, in their free access to God,d and their yielding obedience unto Him, not out of slavish fear, but a child-like love and willing mind.e All which were common also to believers under the law.f But, under the New Testament, the liberty of Christians is further enlarged, in their freedom from the yoke of the ceremonial law, to which the Jewish Church was subjected;g and in greater boldness of access to the throne of grace,h and in fuller communications of the free Spirit of God, than believers under the law did ordinarily partake of.i
aTit 2:14; 1 Thess 1:10; Gal 3:13. bGal 1:4; Col 1:13; Acts 26:18; Rom 6:14. cRom 8:28; Ps 119:71; 1 Cor 15:54-57; Rom 8:1. dRom 5:1-2. eRom 8:14-15; 1 John 4:18. fGal 3:9,14. gGal 4:1-3,6-7; Gal 5:1; Acts 15:10-11. hHeb 4:14,16; Heb 10:19-22. iJohn 7:38-39; 2 Cor 3:13,17-18.
So it is clear from this paragraph that when the doctrine of Christian Liberty was formulated what was in view was the Christian's liberty from sin and their freedom in Christ. It is a liberty from the enslavement of sin and subjection to Satan to brought into the freedom of life in Christ. When this is understood it will be seen how very far today's notion of Christian liberty- which we hear as a constant refrain whenever any issue of morality or personal conduct is brought up- has veered away from how the divines originally understood it.
For what we often hear today is that issues such as the ones mentioned in the OP are left for Christians to make up their own minds about and the church cannot command believers in these areas. The only part of the chapter on Christian Liberty which they could possibly appeal to for such an understanding would be the second where the conscience is spoken of:
2. God alone is Lord of the conscience,k and hath left it free from the doctrines and commandments of men, which are in any thing contrary to His Word; or beside it, if matters of faith or worship.l So that, to believe such doctrines, or to obey such commands, out of conscience, is to betray true liberty of conscience:m and the requiring of an implicit faith, and an absolute and blind obedience is to destroy liberty of conscience, and reason also.n
kJames 4:12; Rom 14:4. lActs 4:19; Acts 5:29; 1 Cor 7:23; Matt 23:8-10; 2 Cor 1:24; Matt 15:9. mCol 2:20,22-23; Gal 1:10; Gal 2:4-5; Gal 5:1. nRom 10:17; Rom 14:23; Isa 8:20; Acts 17:11; John 4:22; Hos 5:11; Rev 13:12,16-17; Jer 8:9.
But even here it is plainly stated that this liberty is a liberty from those doctrines and commandments of men which are
contrary to the Word of God, which contradict commandments found in Scripture. This is similar to when we say that Christians should obey the law of the land in so far as the law of the land does not contradict God's law. But what has happened today is this has been flipped to say that Christian liberty consists of freedom to do as one pleases unless there is a specific commandment in Scripture otherwise (and even when there is an explicit command in Scripture ways are found around this by saying things like "that command is cultural" or "times have changed, practices have changed" &c.)
As we see in the third paragraph the idea that this liberty is, essentially, libertarianism was not what was in view at all by the divines:
3. They who, upon pretence of Christian liberty, do practise any sin, or cherish any lust, do thereby destroy the end of Christian liberty, which is, that being delivered out of the hands of our enemies, we might serve the Lord, without fear, in holiness and righteousness before Him, all the days of our life.o
oGal 5:13; 1 Pet 2:16; 2 Pet 2:19; John 8:34; Luke 1:74-75.
Again we see that what is primarily in view is freedom from Satan and liberty to live a holy and righteous life in Christ.
And then we come to the last paragraph:
4. And because the powers which God hath ordained, and the liberty which Christ hath purchased, are not intended by God to destroy, but mutually to uphold and preserve one another; they who, upon pretence of Christian liberty, shall oppose any lawful power, or the lawful exercise of it, whether it be civil or ecclesiastical, resist the ordinance of God.p And, for their publishing of such opinions, or maintaining of such practices, as are contrary to the light of nature, or to the known principles of Christianity, whether concerning faith, worship, or conversation; or, to the power of godliness; or, such erroneous opinions or practices, as either in their own nature, or in the manner of publishing or maintaining them, are destructive to the external peace and order which Christ hath established in the Church, they may lawfully be called to account, and proceeded against by the censures of the Church,q and by the power of the civil magistrate.r
pMatt 12:25; 1 Pet 2:13-14,16; Rom 13:1-8; Heb 13:17. qRom 1:32 with 1 Cor 5:1,5,11,13; 2 John 10-11 and 2 Thess 3:14 and 1 Tim 6:3-5 and Tit 1:10-11,13 and Tit 3:10 with Matt 18:15-17; 1 Tim 1:19-20; Rev 2:2,14-15,20; Rev 3:9. rDeut 13:6-12; Rom 13:3-4 with 2 John 10-11; Ezra 7:23,25-28; Rev 17:12,16-17; Nehemiah 13:15,17,21-22,25,30; 2 Kings 23:5-6,9,20-21; 2 Chron 34:33; 2 Chron 15:12-13,16; Dan 3:29; 1 Tim 2:2; Isa 49:23; Zech 13:2-3.
Here the divines are quite clear that the church has the right to make laws in regards to personal conduct (or conversation) and to resist these laws is destructive to the peace of the church (this is clearly seen in how these issues have divided the church because the libertarians have done exactly what is being described in this paragraph) and the church has the power- indeed the duty- to discipline and silence these people.
So basically the doctrine of Christian Liberty has been grossly abused in our day- and over the last few generations- to allow the world to come flooding into the church and to allow many things which were once and for a very long time considered unthinkable for a Christian. And to silence all those who would raise an objection as a "legalist".