cured lr has been in a saltwater system long enough for the die-off to basically rot away....die-off has cycled sort of and there will be plenty of life remaining.
un-cured lr has not been kept in a system to allow the die-off to rot away....When placed in a saltwater system the die-off will sort of cycle and when it stabalises there willbe life remaining.
both will have life remaining...*_^...thats what makes it LR.
I prefer to cycle a new system with un-cured lr and try to use cured lr when adding to an established system...
figi lr is my personal choice...but there are numerous types to consider....
I would suggest a total of 1-2 lbs per gal...but this is a personal choice also....in my 55 reef I have approximately 100 lbs of well cured figi lr...in my fish only community system I have maybe 40 lbs(55 gal)...and in my 29 gal aggressive I have only 20 lbs or so(plan to add more to both fish only systems eventually)...the benefits of good quality LR are numerous...but primarily is the abality of the bacteria to process nitrites into nitrates which is a good thing in any system. Plus there will be some un-expected life forms that will show up(some good others bad)....
