Interesting comment about runescape, I mainly play MMO's (Ultima Online, Lineage2, Darkfall and now Lotro) and have never even watched any Runescape gameplay, I'll have to get on twitch and get the feel of it.
I'm going to confirm today how to stop the arrows going through buildings, I thought you just had to make the gameobject static, but I now suspect it has to be rigidbody also, I'll know by the end of the day and do a new build.
cheers