Travelling on an Expired RC

Hi Guys

Hope you can help

I am on an RC expiring end of Dec 2015 - I am an unmarried partner of an EEA national exercising treaty rights.
I would like to travel home to South Africa in Dec my partner will not be travelling with me and would like to know if this would be possible ?

I have applied for a renewal of my RC currently with the HO - i'm concerned that my RC will not come through in time for me to either fly or come back.

1.The reason why I applied for a renewal, I was concerned about the timelines- Ie if I had to apply in August my confirmation of PR would only get issued (according to current timelines) in Jan
2. Thought the renewal would be quicker ( application submitted 1 July) - but looking at current timelines of everyone else im thinking it may be the same as the PR, as they are still working on March.

So - what are the chances of me travelling to SA and coming back the day before my RC expires - or would I be at risk of running in to issues at immigration ?

If i were to get my PR application in like in the next few weeks, would this make coming back easier ? as I would then have an application in for both RC renewal and PR ?

thanks in advanced guys

If you have a valid RC and a COA for renewing where is the problem?

So does that mean I can travel home with my RC that is about to expire - come back through to the uk border agency, produce an expired RC but with my COA ( for current application ) and I will be ok ?

I was just wondering if the UKBA would frown upon my visa being expired- by the time I return ?

thank you in advance for your help