With ENA5 out of the way, it's just ENA6 to go, so good luck for tomorrow.
There are plenty of tips on this blog for how to approach this paper, but remember that reading carefully, annotating well and thinking about the specific demands of each question are the keys to success.
Don't spend too long on parts 1a and 1b: you should be able to get 10 marks for these in about 10 minutes maximum, leaving you about 50 minutes to analyse and evaluate the text for 1c. Remember that you;'re not just feature spotting (although that is part of your job), but you're supposed to be evaluating how the writer of the text represents the issue he or she is talking about. In the texts we've looked at in class (the ones that haven't been past paper questions), think about how the rabidly anti-PC David Gelernter constructed his attack on the feminist "language rapists" as he termed them, or how Michael McCarthy in his "I'm Happy to Boldly Get it Wrong" argued against prescriptive views in grammar and language change. The title of the paper is Language Debates and you will get more marks if you write like you're contributing to , and care about, the debate.
With part 2a, selecting your relevant sources is important: use a range of texts from the paper (and your own ideas and other study) and don't rely too much on the one you've just analysed for 1c. If you feel confident, tie this debate into that of other language topics. PC and Language Change are closely linked. Accents and dialects are changing too - they could be linked into Language Change. It's a synoptic paper, so look for links with other areas. But, be careful not to confuse your reader. You will be writing for a non-specialist audience, so take care to explain technical ideas and don't assume they will know who particular linguists are.
As for my top tips for which topic it might be, I suspect (based on previous papers and topics, not any inside information obviously) it will be either Political Correctness/ Language and Representation or something about Accent and Dialect. For the latter, I'd say look at ideas like dialect levelling and the ways in which new varieties of English have grown - MEYD, Estuary English etc. I got it right last year (attitudes to Language Change) but hopelessly wrong the year before (the speech of chipmunks and cheerleaders) so don't bet everything you have on my predictions.