Google Maps API KEY and 404 ERRORS

Just two last questions BEFORE I ask for refund:

1) HOW CAN I FIX THE GOOGLE MAPS NO API KEY PROBLEM???

I think that it’s related to VC plugin update. Is that true?
Where can I set my own key to this API?

2) Why, in name of God, all pages return 404?
Created 732819378921 pages and none worked
Already tried the permalink flush recomended in another thread without success.

I’m using Nginx with all good practice of wordpress codex.

Thanks.