Lower taxes are great, but if its going to cost you money, it's not worth it. If a stock hits your sell range after 3 months, do you really want to risk 9 more months of fluctuation to get a lower tax rate?
It can be horrendous. There's so much that software cannot possibly know.
The AMT is an entirely different way to calculate your taxes, and it's not really an alternative, as the name suggests. You have no choice. And it's affecting more and more people all the time.
Once you've done the sale, the only way to fix that is with a time machine. But you can take steps to minimize the (tax) impact.
You're going to need all that information to determine cost to calculate your gain or loss at a later date.
It's a gamble for you to try to figure out what is going to happen. Put away what you know you will have. Then put away a little more just to be safe.
The biggest problem is people don't keep good records. If people kept better records, they'd save money.
The biggest mistake regarding record-keeping is not writing things down or not remembering where you wrote it down.
If you can get (the balance) paid by the due date of your return plus extensions, don't do it.