How do I incorporate the Google map but with the custom marker? Do you have any public Google Maps API (which does not require an access key)? Currently I need to include "all" API, just to perform the operation (previously) get a latitude, longitude and marker image and mark the map.
Java Script
To include the map, as you should already be doing and as indicated in documentation , you really do not need any keys to that. So, customizing the bookmarks also does not require a key, just change the parameters of this bookmark, including the icon property, as shown here .
For example, once you have a new_marker.png image in your files, you just have something like this:
var iconBase = 'http://www.seusite.com.br/icones/';
var marker = new google.maps.Marker({
position: myLatLng,
map: map,
icon: iconBase + 'novo_marcador.png'
});