Hi,
1. ways to see if it is unhealthy is that if the pitchers turn brown and the leaves turn brown also, there are occasional that the pitchers turn brown cus they are old and same with leaves, but if its un healthy it may turn brow rapidly and the newest leaves will turn brown also
2. as far as i am concered. alata likes moist/wet soil, dont keep it very wet for long periods of time, and dont let soil dry out
3. is your alata in a terrarium? because if its outside i wouldnt worry about feeding it, it feeds it self becuase flys are attracted to the nectar inside the pitcher and fall in and thats how they feed, but if its in a terrarium, i use meal worms to feed my pitcher plants (sarracenia, nepenthes, sometimes VFT's)
you can buy it at a pet store, get the small babie ones, usualy they are for pet lizards, some people dont use em becuase it turns there pitchers brown but i havnt seen any problems with mine.
4. there is no average number of pitchers, if its healthy, it will keep old pitchers for a long time, and produve new ones, also, it can have very few pitchers if its not grown right and there are only a few of em and the others have died off
5. i dont think you REALLY need to know any thing else, just that there are highland alatas and lowland alatas, and they like i think 75% humidity or above
i dont own a alata but lots of other users do, wait to see what other people post, i think trashcan has a alata
hope this helps