For the issue of having too many channels, when you import the edf file, input those channels:
3 4 5 6 7 8 9 10 11 12 13 14 15 16 20
20 is optional, it’s for the event markers.
This is what I have in my .ced file (for some reason the formating in this forum is terrible though):
Number labels ref theta radius X Y Z sph_theta sph_phi sph_radius type urchan datachan
1 AF3 -23 0.411 0.885 0.376 0.276 23 16 1 1 1
2 F7 -54 0.511 0.587 0.809 -0.0349 54 -2 1 2 1
3 F3 -39 0.333 0.673 0.545 0.5 39 30 1 3 1
4 FC5 -69 0.394 0.339 0.883 0.326 69 19 1 4 1
5 T7 -90 0.511 6.12e-017 0.999 -0.0349 90 -2 1 5 1
6 P7 -126 0.511 -0.587 0.809 -0.0349 126 -2 1 6 1
7 O1 -162 0.511 -0.95 0.309 -0.0349 162 -2 1 7 1
8 O2 162 0.511 -0.95 -0.309 -0.0349 -162 -2 1 8 1
9 P8 126 0.511 -0.587 -0.809 -0.0349 -126 -2 1 9 1
10 T8 90 0.511 6.12e-017 0.999 -0.0349 -90 -2 1 10 1
11 FC6 69 0.394 0.339 -0.883 0.326 -69 19 1 11 1
12 F4 39 0.333 0.673 -0.545 0.5 -39 30 1 12 1
13 F8 54 0.511 0.587 -0.809 -0.0349 -54 -2 1 13 1
14 AF4 23 0.411 0.885 -0.376 0.276 -23 16 1 14 1