It is possible to turn on a soft double beep sound that confirms in OVF when the focus mode switch is set to MF. You use the AF button to manually lock focus. Of course there's the focus DOF bar as well.There is no parallax correction. It is difficult to know exactly where the focus point is especially when the subject is about 12 feet or less away.
In AF mode the double beep sound is still an option in OVF mode. With a shutter half press a new focus box appears inbetween the initial focus region on the screen and the parallax box. When focus is locked the box turns green. If focus is not found he box turns red. The new focus box position is a computed estimate of the actual focus point. The closer the subject, the less precise the estimate. So it is possible the indicated focus region is not where you think it is. However in my experience this is rare. Of course the focus scale is still present if you turn it on.
EVF works a bit differently.