Income tax withholdings are only "optional" if you expect to pay no income tax for the entire year (and the previous year). Other than that, the W-4 you fill out gives you a reasonable number of allowances to declare to determine how much tax (if any) should be withheld. They are fairly accurate unless you have unusual circumstances like uneven income, itemized deductions, or uncommon tax credits.
The main thing you can possibly do is bump up your allowances to reduce the amount of tax withheld, but all that means is that you risk underpaying tax throughout the year, which will result in a hefty tax bill (including penalties) when you actually file. Note that it is technically illegal to falsify any information to artificially increase your allowances, and according to this site you can actually be fined for doing so. That doesn't mean that you have to use the answer that the worksheet gives. I have often declared allowances much higher than the worksheet gives because we had a much lower tax bill when itemizing deductions and taking tax credits into account (which the worksheet's don't always handle well). But blatantly false things like lying about your filing status could be fined.
are there any mandatory taxes that I must pay that are not on that list above?
If there are, I would assume your company would deduct those for you. Note that there are many "taxes" that are not taken out of your paycheck, like property tax, gasoline tax, and sales tax.