If I were you, my short term solution would be to find a hacky workaround to avoid rate limiting. Once I got that working, I'd immediately start the conversion over to OSM or other alternatives.

I'm not familiar with the google maps API so I'm not sure what a "hacky workaround" would look like. But I'd guess that one of the following would work:

- Rotating API keys

- Loading the map in an iFrame from a rotating set of domains

- Pointing multiple domains to the same IP and rotating which domain you use in the embed