You should be unable to access any part of the subnet from the main network unless the tutorial you followed set it up in both directions. As long as the storage bus+interface combo is the only connection you shouldn't be able to access any autocrafting, that means you set it up correctly.
The storage bus side is an entirely independent AE network. The way this trick works is that when you attach a storage bus to an ME interface, the interface does not simply show up as an empty container. Instead it forwards all items stored in the connected network, and the storage bus acts as if all of them were contained in a huge chest. Again, this can only grant access to the stored items. Setting any of the local storage slots on the ME interface also disables this functionality.
You should be able to use export/import buses and similar devices from within the subnet, but test it with a terminal first.
I just figured it out myself, it all matters where the output is on the GUI, for example, the "Basic Factory" has 3 outputs on the bottom of the GUI, so you need to put the import bus on the bottom, and the 3 inputs at the top, so place the export on top of the machine. Think of Export Buses as exporting from your ME system and import importing INTO your ME system.
Input input input |
| | | |
\/ \/ \/ |
out out out |
Well, the last one here said it partially right to solve the problem
But the true source of problems lies within chunk separations.
It's wrong to place buses from one chunk connecting to machine in another.
Actually ANY interactive mechanism from ANY mod is wrong to place between chunks.
There are exceptions, but not very much.
The best practice is building withing chunks and when somehing uniting with any itemducts/conduits/cable, their connectors(from EnderIO conduits) shouldn't be at the chunk separating line too.