No. The speed setting is how fast you ride on a 0% gradient. Your speed will be adjusted for elevation so you are faster on the downhill, and slower uphill, relative to your flat speed - just like the real world.

Yes, currently. I’ve been testing the GPX files for months and none of the rides have been removed.

Not recommended. There will be lots of eyes on popular segments and if an amateur suddenly sets the fastest time, it is likely to get flagged!

It appears that their algorithm may be a little sensitive and produces false positives. Just select ‘Ride’ instead of Ebike and you’ll be included on the Leaderboards as normal.