How do we time ILs? Do we use IGT? Real time? And if it's real time. When does it start and stop? I have some ILs recorded and I'm asking this because I want to have the right timing on them. And the rules for ILs seem to be empty.

In-Level timing is based off IGT

As long as you have footage from when it says "Go!" up until the screencap of the In Game Time level record, that's all thats needed.

Okay, I'll submit my times, for 3Laps and 5Laps, but I have something else to ask. Is the time for 1Lap on the leaderboards the "Fastest Lap" time?

I believe it’s the fastest time yes.

I apologize I've been busy, getting everything organized now. Yes, the "1 Lap" is fastest recorded singular lap in a run. You can do it during whatever type of race, fastest recorded single lap in a video.