Angel Uzi :
i think with lootshare you get some of loot shared between the friends which have it on, with coinshare only certian ppl you selected can obtain the loot or coins. i'm not sure i've only ever used lootshare once.
Theoldpker2 :
Lootshare Increases the chance of getting loot between your team. Coinshare Splits the loot evenly into coins for your team Example: if you get a hilt drop worth just say 20m (not right price i know) and there is 4 on a team you will all receive 5m cash. Hope this answers your question. if not then use the data base to get all the info.
link:
Runescape Gold
Runescape Money
Runescape Power Leveling