Sorry, none of the verses you mentioned refer to vasectomies. Let me illustrate.
Gen 38:9-10 is talking about Onan refusing to fulfill his brotherly duty. That was the wickedness, not spilling seed. Do a word study on the idea of spilling seed and you will find that it is not a sin whether intentional or not. Not in the Old Testament, not in the New. Onan did not wish to bear his brother a child (selfishness) nor did he want to be referred to as the line of the unsandaled (pride). His wickedness was his selfishness and pride, not spilling seed.
Deut 23:1 states that those that have lost testes are prohibited from fellowship. Nothing about vasectomies. Elsewhere, there are restrictions for priests that are disabled. They were prevented from entering God’s presence. However, Jesus reinstates these into fellowship with the following:
Matt 19:12
For some are eunuchs because they were born that way; others were made that way by men; and others have made themselves eunuchs because of the kingdom of heaven. The one who can accept this should accept it.”
No longer are the disabled or physically altered prevented from fellowship through Christ Jesus. No longer are illigitimate children prevented from the assembly (Deut 23:2).
1 Corinthians 6:19-20 is speaking about a christian having sexual relations with a prostitute. Nothing about ejaculations nor vasectomies.
Philippians 3:2 is speaking about physical circumcision specifically and reliance on adherence to the law in general, for salvation, not vasectomies.
If the early Christians or the Pope believe things that are contrary to what Scripture teaches, they are wrong and God’s Word is correct. Satan misused God’s Word and has been doing so quite effectively for millenia. Christ even rebuked Peter because what he said was contrary to not only God’s Word, but God’s will. What man says, or angels or demons say, is secondary to what Scripture says: Gal 1:8.
Finally, Deut 4:2 “Do not add to what I command you and do not subtract from it, but keep the commands of the LORD your God that I give you.”
The Pharisees fell into the trap of adding to God’s Word - and killed Christ to protect their beliefs. Many throughout church history have followed this path of adding to God’s Word and killing to protect that belief. Including the catholic church. And the protestant church.
Scripture is in line with Natural Law. Self-mutilation is against natural law, especially if it is to engage in sexual gratification without the consequence of pregnancy.
Your analysis of Genesis is a little flawed. This is one of the critical verses Catholics rely on to show that God does not want contraception. Why was Onan killed for his “selfishness” by God? God already proscribed a punishment for failing to want to give your brother an hei,r if he has died - public humiliation (Deut. 25:7–10). Why would God impose the particularly harsh punishment of death for Onan for this crime? The answer is simple - Onan did more than refuse an heir to his brother - he used his wife sexually outside of natural law. He “pulled out”.
1 Corinthians 6:19-2 definitely applies. Your body is a temple for the Holy Spirit and it shouldn’t be mutilated or used immorally.
Perhaps some of the other verses are red herrings, as it relates to this topic.
Also, there are numerous mentions of sorcerers not inheriting the Kingdom of God. What do you think a sorcerer is? My understanding is that a sorcerer was commonly considered one who provided abortions and contraception.
Deut 4:2 “Do not add to what I command you and do not subtract from it, but keep the commands of the LORD your God that I give you.”
Well the New Testament right through to the book of Acts is a demonstration of God giving commands. One of the commands He gave was in Matthew 16:18-20. Herein the papacy of the Church was founded - His hierarchy was established. The Gates of Hell shall not prevail against His Church.
God bless.