Same here... You can pop off the inspection cover, copy the vin, and go to the local cop shop too. I had to do that w/ mine.
If they do have the title it is pretty sure it's not stolen BUT who knows the circumstances. Plus it is felony forgery for a second/third party to sign a title. If it's signed before you get there?? Who knows.
The mileage is a non issue. 5k miles in 90 days is just 55 miles per day. I do half of that but live in a 5 mile long town from end to end.
The warranty is transferable, and the manual is free on line Both non issues.
I would ask to see the signed title, and compare the frame number (under an egg shaped cover on the frame down tube between your feet). If the numbers match go to the local PD or DMV, and verify it's not reported.
Nothing worse than going to resister, and having to hand the bike over.