It's anything over £17,775 on Plan 1 or anything over £21k for Plan 2 (Post 2012 course start).
Nope
You might want to wait a week or two
“The earnings threshold will be increased from 6th April 2018. From its current level of £21,000 the threshold will rise to £25,000 for the 2018-19 financial year. Thereafter it will be adjusted annually in line with average earnings.”
Student finance update:Written statement - HCWS145