Tithing Complexities

As I sat in Sunday School last Sunday, a comment was made about General Conference and church meetings how most of them are of the basic and simple church topics like Faith and Repentance. I thought to myself, those are the easy topics? I dont even understand them. There is so much to them and I can always learn more.

Another complex issue is tithing. As a primary child, they say, if you make 10 pennies, you pay 1 to the church and you keep 9. Although simple on the surface, it is a little more complex.

There is the obvious issue of net vs. gross. But if you probe a little deeper, here are some questions.

1) If I participate in my company's 401K matching program, do I need to pay tithing on what my company contributes?
2) Once I am retired, do I need to pay tithing? What if I only live off of what I contributed?
3) What if I own my own company receive many benefits from it: I have a company car, they pay for my computer, gas, trips, vacations, etc? Do I need to pay on their health care coverage? (I recently went to the dentist and the bill was $400, and I only had to pay $67).
4) If I buy a house for $100K and sell it for $200K (obviously not a realistic current example), but do I need to pay tithing on the $100K increase?

There are more, but I will save the agony. That one simple word "annual increase" is actually pretty complex. It is not only cash, property, things, cant it also be considered a cancellation of debt or obligation? If I file for bankruptcy and have $100K in debt relieved, is that an increase?

Thoughts?