Overall design philosophy:

• 5e Classes == good (except wizard)
• Paths are good, if done right
• Feats are bad
• Multiclassing is...a necessary evil? Hopefully not needed, but should be planned for

In this system, relative to 5e and/or Bertball extended 5e:

• Class and Path both give powers every level
• Nobody should get the classic 3e wizard "2 powers per level" shtick
• Did I just contradict myself? We'll see
• If there are feats, they should be rare (like 5e) and very general. Good feats:
  • Weapon or Armor Proficiency
  • Add another good save
  • Gain a new skill
• Of course, along with ASIs, these constitute improvements to your "basics" that should perhaps just happen anyway?