I've been dying to go on a backpacking trip to the Isle Royale but since summers almost over and I'm short on cash so I'm aiming for next year. I have a lot of questions to make sure I am properly prepared and have a awesome trip! I was wondering if you guys could help me out

Background Info: I am 21 years old and will be coming from Chicago, IL. I will be traveling with my girlfriend (same age) and possibly a third. We are both physically fit and have a lot of camping/hiking experience but we have never gone backpacking.
1. What would the best way to get to the island? Driving or Flying to copper harbor?
My first choice would be driving its about 8 1/2 hours from Chicago. After driving should I head straight to the island or camp that night and catch the boat/plane the next day?
2. Should I take the seaplane or the boat?
I couldn't find a price for the plane but I assume the boat is cheaper.
3. What time of the year would be ideal to go next year? I was thinking early spring. What are some of the pros/cons of going early/mid/late in the summer?
4. Okay here's what I've had the most trouble with..planning my trip once I get on the island! I want to stay at least 5 to 7 days on the island. Whats the best possible day by day route/campsites I could do given my time frame?
*Edit* I'm pretty sure I will be arriving at Rock Harbor?