For example: The capacitor symbol has pin lines that are less than 0.1" long. The current version of the symbol editor will not allow me to change the length of the pin.
The symbol editor should allow me the flexibility to re-create any symbol that already exists. User defined symbols should not be hamstrung.
The schematic editor for Quartis (Altera FPGA editor) had this issuer too. After a bit of research, I found I could edit the symbol files in a text editor to achieve the results the built in symbols had. It was painful to do this, and I would prefer it if I did not have to do the same kind of hacks with librePCB.