So basically if he changes churches, he can still perform the sacraments, all 7 of them if he wishes, though they wouldn’t be valid in the Catholic church they would still be valid to God?
They would be fully valid under condition that he actually administers them! For example if Priest went to denomination which denies Transubstantiation, he would not be able to consecrate Eucharist anymore… just because he would not do so. This is my understanding and correct me if I am wrong.
On the other note, even if one Priest became Protestant, next ones would not. Only Bishops can confer Priesthood on other people and hence for Apostolic Succession and valid priesthood you need Bishops. At the same time, if Protestant denomination viewed sacraments differently or understood them incorrectly, then conferring Priesthood would not happen. This is what, from Catholic view, happened with Anglicans.
What does such a sacrament look like in God’s eyes.
What it generally means that sacrament is valid and God, by his promise to His Church, views it as valid and confers grace. At the same time though, it should be avoided to actually administer such sacraments and is irregular way of receiving grace, which can also lead to a mortal sin, as it is grave matter.
Explain that… are we not all changed when we accept the Lord?
Yes and no. While being baptized changed my soul forever, I did not really become Christian until much later. I was not raised in the faith. When I got my first Communion I actually believed in the Lord and everything Church taught and accepted the Lord- but for like a month or two. Then I simply started living old way again. I was changed for month or two, not permanently. I had to accept Lord for second time. However, I did not need baptism as my soul was already changed by it before. I was baptized whether or not I was Christian! And I am pretty sure that grace of baptism also helped Holy Spirit work and bring me back.
When Priests become Priests, their soul changes forever… same as with my baptism. They can lose faith, they can become heretics… but they remain Priests… same as I remained baptized even when I did not believe in the Lord.