Yes, you can bring your own and use the launch in the park, or you can rent from Skip's in the park. Skip's will drive you upriver so you can come down to your car at Delphi. If you bring your own kayak you may need two cars, One to launch upriver (at Hudson Mills) and another one at Delphi so you can go back upriver and get your other car.

There are restrooms near the entrance, and also towards the back. You are probably no more than 10 minutes away from the closest one while in the Park.

Ann Arbor Parks have the following rule: When in a Park no person shall: Consume any alcoholic liquor. However, when the park is open, consumption of wine and beer is permitted except in park drives, parking lots, pools, skating rinks, tennis courts, play apparatus areas, and areas where consumption of all alcohol is prohibited by posted notice pursuant to City Council resolution. The administrator may issue permits for special events to allow the consumption of wine and beer in areas where such consumption would otherwise be prohibited. Thus, some alcoholic beverages like beer and wine are permitted, especially if you get a permit, usually related to renting one of their pavilions or similar to host an event.

Most Ann Arbor parks are wheelchair accessible, at least for the majority of their trails. I have been to most of our parks and cannot think of a trail that isn't.