To add one ship all you need is
#ship classes
[ship info]
#end
by copying the BP file you have duplicated things that the Engine dosent like duplicating like engine wash, also BP and FSO 3.6.14 RC5 dont play well together.
I suggest you wipe out everything in the file, enter "#ship classes" a couple of hard returns and "#end" (Without the speach marks, then copy the entry for 1 fighter and paste it in between, then edit the entry as needed. this way you keep it simple, you are less likely to duplicate things and errors are easier to find, if you need another ship once you have got the current one working just past it between the #lines work away on it