It will also be helpful to understand how the smartthings multi-protocol architecture works.
The smartthings hub is a white plastic box containing four different connectors.
There is a Bluetooth radio which is not currently enabled, so we’ll ignore that.
There is an ethernet connection to your local network which is how the hub both talks to the Internet and talks to other local devices like a Phillips hue bridge.
There is a Zigbee Coordinator using zigbee home automation profile (ZHA 1.2)
And there is a Z wave controller. Zwave plus, actually, but the zwave standard is backwards compatible so it can talk to both Zwave plus devices and Zwave classic devices.
Both zigbee and Z wave are “mesh” protocols, which means they use a relay system so that devices pass messages from one to another down the line. Sort of like pony express riders. This is good, because it means that the hub doesn’t have to be in direct range of each of your devices. Instead, the hub can send out a message to a device in one room, which then relays it to device further away. This is called “repeating.” All good stuff. 
However, zwave can only repeat for Z wave and zigbee can only repeat for Zigbee. And battery powered devices don’t repeat at all, because it would use up the battery. So your typical repeaters in a home automation set up are light switches, outlets, in wall relays, pocket sockets, and plug-in sensors. You basically want one of those for each protocol about every 60 feet for Z wave plus and about every 40 feet for Zigbee. (There are some architectural factors that can shorten the range like foil backed insulation, metallic wallpaper, cement walls and ceilings, brick, etc.)
Your gocontrol sensors and the Aeon Lab sensors are battery-powered zwave devices. Which is fine, they’re good devices. But your quirky devices, which so far seem to be your main non-battery devices, use zigbee. The quirky devices will be able to talk to each other, but they can’t repeat for the gocontrol sensors. So you run a real risk of orphaning your sensors out of range.
Kwikset makes both a Zigbee and a Zwave version of their lock, as do the better quality Schlage and Yale. Most people prefer the Zwave versions because then you don’t have to worry about Wi-Fi interference, but in that case, again, you need to have a Z wave repeating device if the lock is not in the same room with the hub.
So essentially you need to plan for repeaters as though you have two independent networks: one for zigBee and one for Zwave. That may impact your device selection. Iris by Lowes has a good line of inexpensive Zigbee sensors that work with ST if you want to go that direction. Otherwise you’re probably going to need to get some Z wave nonbattery devices.