Access to all powers at all levels after acquisition (maybe not Incarnates) and allow notoriery to be set on all TFs/Missions/Instances
Everything past SBB feels like a race to leave your team behind and clear the objectives as fast as possible. My favorite missions are DFB, DIB, Posi 1+2, Yin and SBB because they require the team to spend a little time interacting with each other to figure out a good team pace. They don't take long and they allow players to focus on using their powers instead of trying to keep up with the person teleporting to the objectives. I understand everyone has different playstyles and my intent isn't to hinder anyone's fun. Having access to all the powers you've gained through 50 at all levels will only increase the fun for everyone. It might lead to more people running +4 DFBs or Posi 1-2s as a fun way to power level friends.
Randomness:
Can the shaking animation from Enflame and Spirit Ward be removed please? Speaking for myself, I've had tanks cancel them because of it.
Vanguard MDC NPC by Ms Lib, +XP gain or some kind of temp buff on defeat, large aoe (a tiny +recovery please mayhaps?)
edit: There would be no change to mid or endgame. People are already supplementing the missing damage powers at low levels with P2W powers. It's the same damage with a much more lame animation.