you will have many advises.
I am myself going through custody battles and issues with ex-wife and oh boy do I wish she was getting eviceted like yours. Not that I wish it for the kids but if a little hurt can bring them 15 years of a better life then so be it.
Let's just say without being a lawyer that the fact that she is in a bad situation is to your advantage. As others said, it's a price to be won and no one in the court system will give much weight to your kid.
However I am from MN and there are a few things that count here especially in the Hennepin county.
1- where the kids go to school and school stability. GET KIDS REGISTERED IN YOUR SCHOOL DISTRICT. pawn your life if you have to. I am kidding on the life part but this is the MOST IMPORTANT thing.
Judges and evaluators look at school stability as a bonnus x10 for the side that has the kids in their school. bad mom or not. where the kids go to school is the key.
2- do whatever you can to make the temporary situation last 6 month.
kids 6month with you plus school with you is a x50 bonnus, .....
If you can have the kids over 6 months and your school in september then wait the summer and wait the 6 month then file for a motion for custody change and ask for a custody evaluation. if you have the above, pro-se or not it's a winner.
3- never, never, NEVER bring the issue of child support
. bite the bullet. be willing to pay it to her even though kids are with you. The court will examin you to see if the reason for custody change is child support and if it is or they believe it, the other barty just got all your points and you will loose.
However, try to never put on paper that you will pay her for ever. the trick is to make it a non issue then after you have custody for a month then go file for a hearing. sure you'll have paid 1 year more than you should but you'll be getting the CS for the 10 years to come after the fact.
Pro-se or not? Lawyers are better however they are not necessary. the court will see to lost soles in court and will not want to decide. They will order an evaluator to do their job and do an evaluation. If you have 1 and 2 and don't care for 3, ... 95% of the times the court will side for what the evaluator recommed.
There are great tips here on evaluation: do not bad mouth the other party, .... and stuff like that, ....
Hope thi s helps, keep us posted in the MN forum