is goku still alive by the end or has he transcended (if i can ask)?
The narrator doesn't consider him "alive" in the same sense as someone as Pan and the TV Special shows he can appear and disappear whenever he wants without it being Shunkan Ido teleportation. He isn't dead either though given the lack of a halo, so it's most likely he transcended to a different state of being as implied by statements from staff interviews about his state of being after getting up from Yi Xing Long's attack; not to mention gaining some form of enlightenment is a fitting end to the character arc of someone based on Sun Wukong.
I'd say Android 8 could be a possibility, since he's based on Frankenstein who's often shown to have an extended lifespan in various media due to being something of a Golem. And I also think we get a glimpse of him in GT looking quite well.
Possibly, though I'm not quite sure when considering he's based on inferior technology to that of Gero's later creations and even his fully artificial ones such as #19 had a limit to their battery life.