Sphinx rerolls my initiative and I roll 22. Do I get an action now or not until 22 next round?

Use action to cast any spell as only used bunus action to maintain?

My DM is trying to make us roll characters changing the dice rolled for stats from 4d6 to 3d6

My DM is trying to make us roll characters changing the dice rolled for stats from 4d6 to 3d6, I’d love your opinion on this.

One guy in our group worked out that it changed the average scores from 11 to 8 which seams really bad.