Very much so. OGG yi-Xiph evulekileyo equlethe, eqhelekileyo ithatha i-Vorbis okanye i-Opus, ngaphandle kokungasebenzisi ilayisensi. That determines both the headroom available and whether the saving costs you anything in fidelity.
Yes — isakhiwo sephepha se-Ogg sivumela ukutywina kwenziwe ngokususa amaphepha, ngoko ke umsindo ohlala ukhona ufana ne-bit-identical kumthombo. It is worth knowing before you overwrite an original you might need again.
Yintoni impazamo eqhelekileyo xa uxinzelela OGG audio files?
No. Cima OGG is free without an account, and nothing is added to the audio. The upload and the result are deleted automatically about 24 hours after the job, which leaves time to download the result.