Just an update: I transferred 5k MR points in, they went through. I was up to 154,000 KF miles. I just got a call from Singapore Airlines. They took the miles out, then took out the 148,750 miles for the ticket and confirmed me. Got the tickets in my email. The original agent reserved me and I was worried it'd go away, but it didn't.

Anyways, I ended up with a Suites ticket in the middle suites back from Tokyo perfect for after the Cherry Blossoms (I hope!).