Using f2wedit_1.4.11.30
Some notes on the app's behaviour. The only really important part is underlined.
Using F2wedit will add folders & files. It creates lst files in: art/critters, art/inven, art/items, proto/items & scripts (unless they already exist), it adds the msg files: perk, pro_item, pro_misc, proto & stat to the game folder (unless they already exist) and it creates a cuts folder (in text/english) (which should be a glitch). Probably pulls them all from master.dat. I compared them to ones I pulled myself from the master.dat and they were identical.
F2wedit does not change files in the text/.../game folder (it only creates ini files (in data/text/game) of "perk, pro_item, pro_misc, proto & stat" and then deletes them again. I only saw changes to pro_item.msg. First, the file's "date" updates each time, so it seems to make a save of it each and every time. And secondly, I noticed the following: First, it removed a space from {23101}{}{ }. Secondly, it removed any space it finds before a } (example: {}{}{farts. }). Basically the same as it does with 23101. AND last but not least, it adds a } to any line that does not end with it. AND it removes any line that does not start with a {. That means the practice of breaking lines (which is normally fine with the engine) will result in f2wedit deleting lines from pro_item.msg. Basically any line break in pro_item causes anything after that line break, and up to the next line that starts with a "{" bracket, to get deleted (tested & confirmed).
F2wedit can read a patch000.dat, but it cannot read a new critter.dat (as FoRes has it, for example). This should not be an issue normally, but if a mod adds something like the environmental armour (as RP mod did) and puts that (plus the lst) in a critter.dat extension, then the reader shouldn't be able to display the model for the armour item... I think? So it [AA frm & lst] would need to be pulled manually. Not a big deal, though.
Anyway, the underlined part may need looking into, as some pro_item files may get lines erased by f2wedit's behaviour.
The rest is just tech stuff, except maybe creating the cuts folder, which is possibly a glitch.