Looks great. Only two things I would like to see added, maybe you already thought of them.
1. Add a Mine Arc. In mods like MiniDW some ships have a HP specifically for the antimatter mines, its arc is usually 0_0 so it can't be used for anything else other than the antimatter mine weapon.
2. Range checker. ShipEdit's range checker kept you from entering too high a number, or invalid character, for certain fields (like putting 14 or A in drone control for OP). The point was to prevent crashing. I don't know any specific limits for SFC3 off the top of my head, but you may want to think about it.