Would this mean that everything else other than those 4 things are just fine for Christians to do?
If one follows the Holy Spirit, folks would spend more time doing what God tells us to Do and less figuring out what they can and can't get away with doing and not doing.
Personally, I eat whatever is set before me with thanks to God. I cook whatever my husband ask me to cook.
with the exception of human flesh or eating animals still alive, God has not revealed that eating anything else is sin.
He makes our body able to digest certain things. As we grow older, we digest less and have to be on a stricter diet. Some people are diabetic and must eat less sugar. I know many who are allergic to certain foods. God is clear what He wants us to individually eat or not eat.
Sometimes He causes His prophets to offend Pharisees because they follow the letter of the law and have forgotten the Spirit that speaks of grace and love.
Don't be a Pharisee or hypocrite. Dont think because you follow a set of laws, you are somehow better than a drunkard or a prositute. Because God loves all His children, even while they are sinners in need of a bath.