Yes, This is what I did and it works fine. The orange plastic just makes it harder to read. Here's what it looks like without the plastic (I rounded the end with a file). The barely visible scratch marks above the top (round) hole and below the bottom hole are where the holes in the orange...
Correct
The outside edge of the tire ends up in roughly the same place. I drove around on it at legal+ speeds on nearby canyon roads and it felt fine
Yes, I'm a retired mechanical engineer :)
Check this out: https://www.integraforums.com/forum/threads/a-spare-tire-that-fits-under-the-load-floor.51812/. I don't know if the load floor is the same for an FL5.
See https://www.integraforums.com/forum/threads/how-do-i-get-rh-side-of-dash-to-display-info-when-vsa-is-off.52045/
If you find a solution, please post.