Any chance of not losing abilities when doing low level dungeons?

[Felis]

As they nerf stats, they could also nerf skills potency, also they could just lower the level to the minimum entry -3 levels by sync only. So for example, first dungeon being level 15. As a sync, you enter level 12. Nerfed skills and lower stats so your damage is even lower than a normal level 15, but you keep your skills.

Only if the skill from a higher level get scaled down.
Say a level 30 skill at level 15 is weaker than at level 30. A level 15 skill at level 15 is stronger than a level 30 skill at level 15.
The player keep the options to use his high level rotation, but it would be much better to use a low level rotation.

OP want his/her lvl 50 abilities not because its hard but because it's boring to go back to spamming one button. I'm gonna assume you're only pretending to be dumb

Bard?
As Monk I press 5 buttons in Sastasha