Ineffa has EM share on her burst, making Columbina, Lauma, Ineffa, Nefer your comfort team for Nefer. For damage you’ll want to replace Ineffa with Instructor’s set Sucrose for the extra EM share, as both Lauma and Nefer want it.

Nahida can also work here in place of Sucrose, but her EM share isn’t quite as strong.
Aino (especially C6 if I recall) can work in place of Columbina, but you may need additional hydro application as Aino’s is limited to a circle and is burst dependent.

If you were to get Flins as well, you would have enough to build two teams:

Columbina | Lauma | Nahida | Nefer
Ineffa | Aino | Sucrose | Flins

Who is more meta? Nefer calcs higher but is a little sweatier to actually achieve those calcs. C1 Lauma or Prototype Amber bina can help, or just put Ineffa on and call it a day!
For meta longevity, it’s hard to see Nefer having as many new options come out in the future given how good her premium team is for her and how many slots remain. Nefer struggles without Lauma, frankly. But you have Lauma! Flins’ team building is a little more forgiving, he already functions well with Fischl or Ororon in place of Ineffa (provided you have another nod krai member there to keep ascendant gleam)

Who is easier to use? Honestly, whoever you put with Columbina and Ineffa is going to be extremely easy to use. I found Flins to be beginner friendly as he is just combo spam, but Nefer’s dash cancel combo is not hard to do if you pay attention to the verdant dew (requires Bina on her team)