I had to end up using another method to get the tp home functionality to work. The tp home link in the book now teleports the player to just above an End portal, which then teleports players within a radius to just above the portal out of the End.
I had to also create an end portal in the Nether at the same co-ords as in the Overworld (which you can do - forums were unclear about this), so that the same functionality still works in the Nether.
The set home link in the book now sets the players spawn point. So, if they die or tp home (tp to end portal then tp to portal out) they'll end up back at their home.
Hope this was helpful to someone else with the same issue.
The way I can think of this works rather well. It involves the "arrow storm" activator being in a specific inventory slot, as if like an option.
First, you set a loop command block to this:
/replaceitem entity @a[m=2] slot.hotbar.0 minecraft:arrow 1 0 {display:{Name:"Activate Arrow Storm",Lore:[Select this slot to activate an arrow storm!]}}
Then have another loop command block activating the following:
/execute @a[tag=SelectedItemSlot:0,m=0] ~ ~ ~ summon arrow ~ ~10 ~ {Life:1000,pickup:0}
Along with another loop that does this:
/execute @a[tag=SelectedItemSlot:0,m=0] ~ ~ ~ summon creeper ~ ~9.9 ~ {ignited:1,ExplosionRadius:1,Fuse:1,Silent:1b,NoAI:1b}
I added tags to the arrows so that they could not be picked up {pickup:0} and despawned after 200 ticks {Life:1000}
The creepers are so the arrows fly everywhere, while allowing for the safety of the buildings if the command
/gamerule mobGreifing false
is executed. Notice that the creeper is slightly lower than the arrows so that they mostly fly upwards.
Have fun with your new arrow storm, or potential entity fountain! ;)
May require a powerful computer depending on how many people are going to use this.
May require several /replaceitem commands to get rid of any arrows created by moving the arrows in the inventory.
Best Answer
So the command to copy a location relative to the execution location (command blocks location or yours if you use command window) is as follows:
/clone ~x ~y ~z ~x ~y ~z ~x ~y ~z. Count the number of blocks from your execution location and use that for your x, y, and z coordinates.