The last bit is funny
Just wondering about the editing photos on Google Drive part: seems like if you set up a Google Drive folder on your desktop then this would act the exact same way. I haven't worked with photo editing software like photoshop or gimp with a file stored on Google drive but I don't see why it would be any less seamless than iCloud...
Google Drive and Google Photos aren't the same service. You cannot access auto backup photos from Drive - at all, period. They do not show up in Drive. You'd have to download them (or import with Picasa if it can see the Auto Backup Albums, im unsure if it can) and then re-upload them to Drive (by copying to the Drive Folder assuming you have it installed on your PC).
Photos in your iCloud Photo Stream, Photos and Videos in your Shared Photo Streams, and soon the entire iCloud Drive all show up in Windows Explorer with iCloud Control Panel installed. Photos are not walled off the way Google Photos is. They are accessible in the most trivial manner - right in the platforms native file manager.
All you need is the Control Panel installed, which is analogous to Google's Drive App for Windows, and to enable Sync for iCloud Photos.
If you know a way to access Auto Backup photos from Google Drive without manually moving them there, which requires an Import and move on the PC (only made easier by installing yet another app on your machine - Picasa) then please let me know!
Personally I use OneDrive for Auto Backup (on my phone) and the Windows 8.1 Photos App for quick edits, which is surprisingly good at what it does, on my PC. What services I use is governed by how well and easily they work/integrate with the other devices I use - I use my PC a lot.
When I had an iPhone I used iCloud and installed the Control Panel to Sync my Photo Stream to my PC. Works similarly, but use uses more storage than SkyDrive's Smart Files.
You cannot auto backup to Google Drive without using third party apps, and I typically only use first party apps to access services where personal information may reside. Not cause I'm paranoid, but because I'm proactive
In any case, I save RAM and device storage by Uninstalling Updates and Disabling the Drive App and avoiding such 3rd party apps, and using One Drive instead.