401K distributions made when you are over 59 1/2 are taxed at your normal rate. The tax rate will vary by individual.

There are no additional taxes or penalties if that is what you are concerned about.

20% is withheld if paid to you. To be taxed at your normal tax bracket, you will have to roll to an IRA, where distributions are then counted as income, taxed at your normal tax bracket.
Some states require withholding as well, AK, CA, DE, IO, KA, ME, MD, MA, NE, NC, OK, OR, VT, VA-- if you let me know the state, if it applies, I can let you know the percent that must be withheld.

Yes, you are.

The whole idea behind the 401(k) is that most money goes IN to the plan tax free, earns tax free throughout your working career, and then is taxed when it comes OUT of the plan. Uncle Sam will get his tax money.

Exception to this would be for certain money types like "after tax" money that you might have put in after taxes or the newer "Roth 401k" money if you contributed that.

The rate that you will pay is simply the same rate that you pay on your tax return for you income, and is therefore dependent upon your tax rate. It is true that the company cutting you the check will withhold 20% but you will still end up paying the difference between that and your tax rate when you complete your tax return.

The fact that you have achieved the age of 59.5 does not excuse you from paying taxes when the money comes out.

It is taxed at the same percentage as income from wages. It is added to all of your other ordinary income which includes income except capital gains. Federal and state tax tables will be able to tell you what tax bracket you are in for state and federal taxes.