Using AWS Direct Connect, is it possible to:
I know just enough about networking to be dangerous, but by no means an expert. Answering in a way that a non-network admin can understand would be appreciated.
The short answer: yes and yes
I'm assuming that you won't be setting it up yourself, that should be done by a network admin. Assuming they have set up the interfaces, router configuration, firewalls, NACLS, routing tables, etc.
You only need to do the following for a specific usecase within your AWS Account:
You can then talk to the on premise servers as if on your own network.