Generally, social security benefits will only be taxable to the extent your "provisional" income exceeds the base amount of $32,000. You are correct in that your benefits will probably not be taxable, however, social security benefits because they MAY be taxable are still considered to be part of your gross income for purposes of determining your filing requirement. Thus, because the benefits you receive exceed the filing requirement threshold (i.e. $7,950) you have a filing requirement, but likely no tax due.
Should any portion of your Roth IRA distribution be taxable because it constitutes a withdrawal of earnings in excess of your non-deductible contributions, since you are not yet 59 and 1/, the 10% early distribution penalty will apply to this taxable portion (if any) of your Roth IRA distribution. This also creates a filing requirement.
However, you may be exempt from paying the penalty tax on the taxable portion of your Roth IRA distribution (if any) if you are considered to be totally and permanently disabled (i.e. your disability is expected to lead to death or last for more then 12 months).
If you do not qualify for this exception you may qualify for the medical expense exception. To the extent you have deductible medical expenses (i.e. medical expenses in excess of 7 and 1/2% of your AGI) you may exclude your taxable Roth IRA distribution from the 10% early distribution calculation. You need to fill out Form 5329 when you file your tax return in the year you make the Roth IRA distribution.
You appear to be eligible for the homestead property credit. When you complete your MI tax return make sure you complete Form MI-1040CR to claim your credit. See the following website for copies of the forms and instructions.