Streaming updates are working fine on my computer, may I simply disable automatic update, which may be unnecessary?
No.
In the automatic vps updates detections are added that are not distributed with the streaming updates.
For the best protection you will need both enabled.
Streaming updates are meant as an addition to ordinary updates of the virus database (to fill in the gaps between them), not as a replacement.
Actually, if you disable automatic updates of virus definitions, the streaming updates are disabled automatically as well.