Welcome back!
Yes, a lot of new things have been introduced, quite a few new courses for instance. Lately, it has been more of childish gadgets as the "cat" balls :(
Concerning levels, see this reference list. Yes, it's becoming steeper - double XPs will bring you to L41 only. The real grind begins at L89 though...
If you're interested to rise, try to use the Continuous Days Bonus - explanations on the Main Game Screen. It's interesting because higher levels unlock better equipment which you might need for higher tiers.
No clue about the capitals for the tier (Tour Pro) - I see yours in regular writing. Tiers are combined with the average and the number of ranked (strokeplay) rounds played - another grind once you arrive at Master...
Most important: Have fun!!