First of all - welcome to the Forum! Great to have you sharing ideas and thoughts here.
Sharing my perspective on the options as you listed them.
Option 1
The ol’ “node vs street” debate… it’s an oft-recurring subject here, and if interested, you can see what others have discussed about it in just a few sample threads:
Node-hunting isn’t the only factor; people can mark streets complete manually, edit .gpx files, change bike rides to run/walk… there are many ways someone could achieve completion that you may consider ‘cheating’. I think in general one has to accept that people use the site as they see fit, and it’s not policed.
Option 2
The idea of averaging lines or snapping to roads has been discussed here:
It seems like there’s strong aversion from making single lines the default option, however you’re proposing a setting toggle where you could do that. My (uninformed) guess is that would be programmatically and computationally expensive to do.
In terms of privacy concerns, there may be more optionality than you currently know. Check out these posts to learn more:
Additionally, while manual, you can always delete specific runs, or edit routes in other programs before loading them. I acknowledge that’s a heavy lift, but you could address all your concerns this way.
Overall
My two cents is this seems like a lot of development work for a relatively fringe case. I don’t mind the existing options; if you want to share you can, if you don’t want that’s fine too.
I’m ambivalent-to-supportive of the idea of a user being able to display their name without displaying their lifemap. While it doesn’t scratch the itch for others users to see their ‘competition’, it does personalize it a bit with a name & a picture.