I believe the answer to the whole 'when is it acceptable to divorce/ are we bound to our spouse?' question lies in Deuteronomy chapter 24...
Deuteronomy 24
Law Concerning Divorce
1 “When a man takes a wife and marries her, and it happens that she finds no favor in his eyes because he has found some uncleanness in her, and he writes her a certificate of divorce, puts
it in her hand, and sends her out of his house,
2 when she has departed from his house, and goes and becomes another man’s
wife, 3 if the latter husband detests her and writes her a certificate of divorce, puts
it in her hand, and sends her out of his house, or if the latter husband dies who took her as his wife,
4 then her former husband who divorced her must not take her back to be his wife after she has been defiled; for that
is an abomination before the LORD, and you shall not bring sin on the land which the LORD your God is giving you
as an inheritance.
The above passage is pretty clear if you ask me. If a man divorces his wife he CANNOT take her back once she has become another mans wife,
regardless of the situation, for she has been defiled and that is an abomination in the Lord's eyes.
As for reasons the Lord would accept divorce.. there is ONLY ONE!!! Sexual immorality/unfaithfulness...
Matthew 5:31-32 (New King James Version)
Marriage Is Sacred and Binding
31 “Furthermore it has been said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’
32 But I say to you that whoever divorces his wife for any reason
except sexual immorality[a] causes her to commit adultery; and whoever marries a woman who is divorced commits adultery.
You are right, people make all sorts of justifications for divorce, ie: abusive spouses and whatnot. I agree that it is not a good idea to stay in a realtionship that is abusive or unloving. But it does not justify divorce. There are other options seek counselling, or remove yourself from the situation while the other person gets help. There are loads of options available. This is not just me speaking. I didn't write this stuff...it's straight out of God's word.
Hope that helps