Yes, each new alpha should have just one version of safe_vault to run if you want to be a node (ie run a vault).
alpha 3 will release safe_vault with routing only
alpha 4 will release safe_vault with both storage and routing
This is only for alpha 3. Once past that, there will be no option (from my understanding) to do routing only.
Farming will happen after alpha 4 (again, just from my understanding, see the roadmap which says test safecoin comes after alpha 4).
Alpha 2 has only one way to interact with the network, ie as a client using the browser and authenticator.
From alpha 3 onward there will be two ways to interact. As a client like in alpha 2, or as a node by running a vault. The two ways of interacting are unrelated to each other. Users can choose to do one or the other or both.
- Alpha 2: client mode only (using browser)
- Alpha 3: client mode using browser and / or run a vault (can only do routing)
- Alpha 4: client mode using browser and / or run a vault (can do routing and storage)
- Alpha ?: client mode using browser and / or run a vault (can do routing and storage and farming)