Instructor pilot noted several taxiway and runway signage problems in ILM.

Narrative

Traffic exiting the South ramp may taxi onto the ILS critical area or active Taxiway E before being in contact with ground control. Contributing Factor is that the South Ramp is involved in 14CFR 61 flight training operations with student pilots on a regular basis. Also; the runway holding position sign is incorrect at the beginning of Taxiway E. Since there is no useable runway left at Taxiway E for Runway 17; the sign should be: E35 not E35-17. This incorrect sign implies that a pilot may turn left to back-taxi to Runway 35. Since the tower is closed at night; this incorrect sign could cause someone to taxi into the soft grass attempting to use all runway length for Runway 35 at night; or combined with a little confusion may cause an accident during the day. If you back-taxi on runway 17 from the South ramp; there is no direction sign for runway exit for a left turn off the runway onto Taxiway B. ATC will sometimes back-taxi traffic on Runway 17 to Taxiway B; and when Runway 24 is in use; traffic may miss the 'right on Taxiway B' since it is not marked. Traffic landing on Runway 35 and taxiing to the East ramp may also be affected by the missing direction sign.