1) No
It's a pity; I liked the GitHub repo

2) Objects are no longer stored in OpenStreetMap. I had quite a long discussion with OSM folks some time ago and they were not very happy about the low quality (missing addresses, etc). of Bitcoin-related OSM nodes. So I decided to do just one-way sync (from OSM to coinmap).
I'm an OSM contributor, and I would have preferred to see wrong nodes removed (or fixed).
Ciao!
Does "one-way sync" mean that if i add a point on your site, it won't be added on OSM? Am i right?
Correct. See the reason for this above.
As I wrote, I don't like your choice at all.
Unfortunately I think I'll search for an alternative.