Michigan state income tax is right around 4% and the sales tax is 6%. Federal
taxes are 7.62% for "FICA" (that's Socialist Security and Medicare) and Income Tax is bracketed based on income level, deductions, etc.
On insurance, it depends if your employer is offering a health plan as part of your job - most do. If your employer offers multiple choices (as mine does), you need to examine issues like your age, overall health, whether you or any family members take "maintenance" medication (like blood pressure pills) etc. In general, if you are in good health and don't have any on-going conditions, opt for the less expensive plans that will have higher deductibles. If regular medication is going to be important, I would choose a plan that has good prescription coverage, unless the medication you're on can be had in "generic" form. Although most employers offer a health plan, employees typically have to pay something towards premiums. This can vary quite a bit depending on the employer, but typical premium contributions can vary anywhere from $0 up to $250 per month. But that's better than paying full price at $500-$700 per person! The good news is you'll get to choose your doctor, and won't have to wait so long for tests and treatments. More things are covered but there can be co-pays.
On deductions and taxes in general, the IRS classifies taxpayers INDEPENDENT of their immigration status. In other words, you can be classified as a U.S. "Resident" for tax purposes, even if your status is actually something else as far as USCIS is concerned. One has absolutely nothing to do with the other. Under current IRS policy, moving expenses are generally deductible (check the IRS website for specifics). Mortgage interest, property taxes, and the like associated with property you may own/purchase here in the States is also deductible.
I would say, check on the IRS website to see how you will be classified for "Tax Purposes" then compare to your tax situation in Canada. It is possible, depending on your specific situation, that you may be able to "choose" your poison - so to speak. In other words, pick the deal that results in the lowest tax bill. That is a possibility, so read the rules carefully.
Ann Arbor is a nice town - lots to do there, good restaurants, some culture, the University, etc. But it is a bit pricey. You may want to look at some of the more "suburban" areas around Ann Arbor for better real estate deals. Having said that, the Michigan real estate market is in the TOILET right now, so it's a buyers market BIG TIME! If you plan on being in the U.S. a while, you can probably pick up some really fine real estate in Ann Arbor for a good price, and, when the market inevitably picks up again in a couple of years, stand to make a nice gain on your acquisition. Ann Arbor is always a very desirable area for buyers.
Hope this helps. Cheers, and welcome!
Snowdog