So upgrading to VSC 4.2 won't "impact" the production environment; in addition to the bug fixes, it has new RBAC features, but this won't break anything (especially if you test/keep it using Administrator and root accounts for vCenter and the controller respectively).
With the version you're running, the likely "answer" for why you can't see the interfaces/volumes "sometimes" is due to a known issue which was first patched in 4.1p1, but is fully QA'd within VSC 4.2, so 4.2 would be the recommended upgrade path.
When the controller is added to M&HC, regardless of which of the IP's appears within that screen, it will enumerate all IP's from that storage controller; in 4.1 it may not do that due to the aforementioned bug.