BingMaps satellite layers + MapsEngine functionality + kml + convenience - maybe?

Question

OpenStreetMap

The bottom line is this:
There will be a lot of maps in my project. But there are personal preferences in certain moments for various vendors.
- Madly in love with satellite images from Bing and their map design (that is, a hybrid).
- Fully satisfies the current functionality of MapsEngine, but this is not so important.
- It is important to connect kml-files.
- Full customizability of maps (management of layers, points, etc.)
_ Control of the display of elements (colors, elements, shapes)
How you want to do it:
Take the necessary layers from Bing, put some layers from OSM on top, maybe from someone else Then, add your route via kml, attach user-friendly GUI controls to that, and paste it into your site.
It is clear that there is no such right service. Although WikiMapia is somewhere close, but I didn’t understand how to make my own routes there and then insert them.
But I want to at least understand which direction to go and what to study. What do you suggest, friends? Where to dig, what to read? My eyes were completely blurred already from the whole variety of services and their complete or partial inconsistency with my needs.