Saving dihedrals, angles, bond type and improper information in dump

Reply to the mailing list and not to me.
This is something you have to figure out. You have to use a topology builder. You cannot (or rather should not use lammps) as a topology builder.

Try topotools.
https://sites.google.com/site/akohlmey/software/topotools/topotools-tutorial---part-1