most work but you need to know what your doing,
need fixing or altering are
theatre pack not bought
horror gore pack ( with chainsaw ) never bought
zombie apocalypse script and fpe editing needed on the mob zombies
viral outbreak pack a lot of work needed to make it work, changing shaders and changing scripts.
nature pack needed a lot of altering as in fpe changing collision modes and a main issue had default static which i oversaw for ages till i erased by accident then i could move, then had to change transparency for trees to be fully visible.
so the answer is yes they work but you will be at it for ages. messing about but worth it for you to have a go as you will learn heaps and feel proud to of done it.
will need gimp, paint net , note pad , lots of time, and if it all goes wrong re install the pack so nothing to lose all to gain.
a few pointers are
textures which are what go on the models ( the paper to hold the paint as it were) need to be dds format ( paint net and gimp) do this conversion for you.
fpe fps fpi are the glue to the game
fpe are for entities and hold the info as in what mesh and animations to height and sounds etc.
fps segments are made with these.
fpi the brains behind it, headaches a plenty are coming your way but it is logical and once you get the jist you start to speed up and things fall into place. as i say though its a long road and suggest check out all aspects of the fpscx10 dabble look explore gutt it and put it back and this will make things easy in the end
s.b.
an unquenchable thirst for knowledge of game creation!!!