How to free up iCloud space from pictures

iCloud tells me Ive run out of space for backups.

I am backing up my iPad which has very few photos and my iPhone which has a lot.

Storage & Backup reads:

iPhone 3.7GB

iPad 364MB

Docs&Data 8.6MB

Mail 312.2MB

Available 643MB

Drilling down into my iPhone

4.4GB Next Backup Size

4.1GB Camera Roll

151MB iBooks

22MB Twitter

12MB Whatsapp

5MB Waze

Anwyay, we can see the culprit here

My Photos App Shows this:

Camera Roll 414

Photo Library 2459

Last 12 Months 407

Last Import 23

My question is how should I manage this in a smart way?  My iPhone is 32GB.  I have quite a bit of free space.  But how does this really work?

As I take pictures, I want them backed up on the cloud in case something happens to my phone.  Once I plug it into my mac, those pics in the Camera Roll go into my Photo Library, right?  So if they are in the Photo Library, I shouldnt need to back them up to the cloud anymore.

So here is my question...I actually have duplicates on my phone right?  I can see those 23 last imported pictures, they are all in the Camera Roll but they are also in the PhotoLibrary (on my iPhone).  If those 23 pics are in the Last Import, that means they are backed up to my iPhoto app on my mac.  Which is why they show up on the iPhone's PhotoLibrary folder.  So there is no sense in having them in Camera Roll as well, is there?  Taking up valuable iCloud space...

How should I proceed?  I want to free up the space I have in Camera Roll by having all those pics and movies show up in PhotoLibrary and have a hardcopy on my ssd but I dont want them backing up into iCloud.

I DO HOWEVER, want to maintain the iCloud-CameraRoll-backup feature activated so that pictures I take today until the time I backup to iPhoto on Mac, are backed up to the iCloud.

phew!