Hello,
when i use Search tab and it return some result from my computer i would like to right click it and play the video/audio. Though i do not see Open menu entry.

you have to download the video to watch it.

Streaming audio over the high latency 3-6 anonymous server tor hidden network is possible however that bandwidth would be subtracted by any other concurrent DarkMX or other Tor networked applications the source is also concurrently uploading, with adequate buffering by the 3rd party player its somewhat usable provided the above stipulations, otherwise the stream will routinely stop, refill the buffer and then play which is a no-go to most.

Streaming video over the tor hidden server network is often at the limits of 3rd party video players buffering resulting in a play, wait, play while consuming to much bandwidth thus its often seen and held as not viable.