Hey 40cal.
I don't have any experience with the 40 cal version of the FNP but I do have the 9mm version. I heard about the gouging on the slide (only on 9mm and 40 as far as I know) too before I bought mine and ended up doing a ton of research on it. First off, yes it does happen. Second, from what I've heard, it gradually happens throughout the first 1000 rounds or so but doesn't get any worse after that and doesn't affect the function of the gun at all. I am getting a little bit of gouging on my fnp9 and I can take some pictures of it if you would like me to. I have about 500 rounds through it so far and just a very slight gouge on the slide under the "P" on "FNP-9". It would take a VERY trained eye to notice it with the gun assembled.
As for the round indicator, mine works fine but it is the 9mm version so i suppose it could be different for the .40.
Let me know if you would like the pictures and I'll get them for you
(I bought my FNP about 10 months ago brand new and honestly have no clue how old it is so they probably could have fixed the problem since then but I don't know)
EDIT: I found the test brass that came with the gun and the envelope it is in says test fire date is 1/15/07 so I guess this probably doesn't help a whole lot. I guess if you still want the pictures just let me know but otherwise, I probably wont be able to help much.