Gonna be short as I've got other stuff to do this morning; Resupply - basically the AFK/farming reason. I kind of feel that resupply should be moved into its own building which could deliberately be used for farming (spawn mats over time, put in coins for burst production for 30s or something), instead of resupply at various other shops "for free". As you say, it discourages collecting mats, but I think it would even more if you could resupply with any amount of inventory. Backwall and spikes: no, it's not meant to be annoying, the builder hit code is just a nightmare for a mixture of "technical problem" and "real problem" reasons. Spikes en masse are best removed with a keg or mine explosion. Bomb arrow damage radius: 48 units, 6 tiles. Half of that is higher dmg. Map damage radius is separate.