No, I'd say its fairly reasonable to require a reason to fire somebody. And who are you to say having sex before marriage is immoral? I'm sorry but if you're getting your morals and judging others from a 2,000 year old book that tells you to stone gays to death, burn cities to the ground for worshipping another God, to murder a female rape victim because its her fault she didn't scream loud enough, sell your daughters into slavery, own slaves, forbids people who wear glasses from going to Church, forbids you from wearing clothes made from a blend of fabrics, forbids round haircuts, forbids farmers planting 2 crops in the same field... I could go on... for a long, long time. If you're getting your morals from a book that teaches all that and more, any reasonable person would laugh you out of the room.
And don't give me any guff about "Thats in the Old Testament!" According to Jesus in the New Testament, the Old Testament still applies.
You have absolutely ZERO idea of cultural-historical context. Also, you made up a few of your own that has no reference. There is no reference in the OT with regards to stoning rape victims. You're mistaking that for the Quran.
The OT does apply. That's right. I said that. Jesus validated the canonicity of the OT. The OT is the foundation of the NT. There are three types of laws in the OT. First are moral laws. It adheres to the very character of God, and are direct commandments. This includes things like you should not steal, murder, etc. Second ones are civil laws. It provides a guideline of how people should live, but may not be applicable directly today -- but there are timeless principles. Third are ceremonial laws. These directs on how to worship.
With regards to farmers and mixed clothing, these are not moral laws. There is nothing in Hebrew context that suggests these are moral laws, nor does it carry over to the NT in direct context. For example, weaving two types of cloths together in clothing is a pagan practice that regards fertility. And of course, counting how people worship other gods at the time (Temple prostitution, human sacrifices, etc) I doubt even these will be tolerated today. This is no different than saying you should not wear the symbol of peace backwards in Germany and stretch out your right arm at a 45 degree angle. 2000 years later people would think you're retarded for making such a law, but there are principles to it that are timeless.
The strict laws of the OT shows the importance of God's saving plan and God's intention to ensure it will be established (Jesus), the strict requirements of God's kingdom, sin and human weakness, and the need for grace (Also Jesus). Salvation is by faith alone, and the substitutional sacrifice of Jesus atoned for all sins. All sins are forgivable except for blaspheming against the Holy Spirit (Which is a sin that cannot be committed in modern day context, another discussion).
I could go on... for a long, long time. If you're getting your ideas with absolutely no background knowledge on what you're reading, and make up a few of your own, any person who has spent about 5 minutes on the internet researching will laugh you out of the room.
I do not believe morals will change over time. Everyone has their own set of morals, and are distorted to different extents. But there are absolute standards. The Bible holds morals to God's standards, and it's reasonable and logical. We can all agree on how we should not lie, rape, cheat, steal, murder, whatever. Some people don't hold to that. Some people have no problems eating other people, and honestly, if there are no absolute and reference standard we can hold to, then I will see no issues with any of the listed items. However, in real life, this does not, and should not, change. If you're tempted to take me out of context, then I have no words for your practices but to shake my head in disgust.
NOTE: I have no background in theology. I am just a guy who does a lot of reading and a lot of research on everything.