I’m confused about what you’re asking for.
First of all, your smartthings hub never shows up as a device in your echo app, because it’s not a controllable device in and of itself. The integration between echo and smartthings occurs at the cloud level, not between the hub and the echo device. If you can see the devices that you have connected to the smartthings hub In your echo app, then your echo account successfully connected to your SmartThings cloud account, and that’s all you need. So that part sounds good. 
Similarly, echo will not show up as a device in your SmartThings account because it is not directly controllable.
As far as using echo speaks, that’s going to work because you will set up an Amazon Heroku developer account to control the echo. You can do that if you want, and it used to be a very popular integration, although technically quite a bit of work to set up.
The newer alternative is just to use the official echo routines feature (not a SmartThings routine) and then you could have the echo say whatever you want pretty much whenever you want to. But you still won’t have the echo device show up in your SmartThings device list and you still won’t have the smartthings hub show up in your echo device list. Instead, you will create a virtual sensor in SmartThings which will show up in echo and can be used to trigger an echo routine.
The following community FAQ explains how to do that if that’s what you want:
FAQ: Can I trigger an Echo Action without Speaking to It?
Or you can go ahead with echo speaks, which can do a lot more, and there will be lots of people who will help you with that. You just need to ask in the right thread.
But the first thing is to understand what the integration is. You’re not going to see echo as a device in SmartThings, and you are not going to see the smartthings hub as a device in the echo app. That communication occurs cloud to cloud at the account level.
Did that help any? Sounds like you’ve got a good start if you have your SmartThings devices showing up in your echo app. It’s just a question then exactly what you want to accomplish as far is the best way of doing it.