My wife and I live in Michigan with our 13 month old daughter, but there has been talk of divorce lately. I'm curious about what types of things matter in a custody dispute. Here's a brief picture of our situation:

Mother's current state:
- Illegal immigrant
- No high school diploma
- Has 2-3 days of alone time with our daughter a week (while I'm at work 7am-4pm)
- Currently on anti-depressants for postpartum depression
- Police report filed for domestic/child abuse, but did not press charges
- CPS has assigned her a counselor
- CPS has threatened a court order to force her to take her medication
- CPS will remove her from the home if a court order is filed and not followed
- Unable to support self on current income
- If divorced, she would most likely move in with her grandmother in Illinois where currently 6 adults (all illegal immigrants) and 5 children (2 illegal immigrants) live
- Threatened to take our daughter to her country of origin
- Has used multiple identities for various reasons (acquire a car, bank account, loans, etc) before our marriage

My current state:
- US Citizen
- Six credits away from graduating with a Master's degree in Education
- Spend 3-4 nights a week alone with our daughter (while my wife is at work)
- Took antidepressants in 2003 for 6 months, no issues since
- Currently supporting my daughter and wife
- Paying all bills (rent, utilities, etc)
- No police record

Status Quo:
- Married almost 2 years
- No shared property (we rent, I'm titled on my car, she is titled on hers under a fake ID)
- I am primary care giver (see above notes about time spent with our daughter). When both my wife and I are home, I typically tend to our daughter while my wife is either sleeping or watching TV/playing video games.

I guess that wasn't as brief as I wanted, but I hope that gives a good overall picture of things. Out of the things above, which items are pertinent in deciding custody? Additionally, I've been keeping a diary of the times my wife threatens suicide, tells our daughter she doesn't want her, or is generally irresponsible (like the time she put our daughter in the high chair and didn't lock the tray or buckle her in, then left her unsupervised....you can imagine what happened. For the record I was hauling in groceries and walked in just as she tumbled out). Do these things matter and are they admissible?

The other thing I keep track of is when and where my wife leaves dirty diapers. This is daily. I come home from work and have to find where she left all the dirty diapers (on the bed, under the bed, on the floor, in the bathroom, in the living room, etc). Is this relevant?

Thanks in advance for any advice!