Questions about responsive versus mobile

I nearly wrote “anguished” questions in the subject line! Can some kind person please offer some guidance about how to make a small site tablet-friendly?

Background: I have two small text-based sites (www.livenowlovenowhealnow.co.uk, 2012 child; bristol-stop-smoking-hypnosis.co.uk, vanilla 2012). My clients certainly read them on tablets and larger mobiles. They do not have to look perfect, “good enough” is good enough. I have reasons to think clients do not read them much on small mobiles, here “adequate” is enough.

One BIG concern is that I do not get errors about mobile screen size in Google Webmaster Tools – that is essential.

Another big concern is that what I do is SIMPLE. These are small, simple sites. I need them to be readable and future-proof, but definitely no overkill and no search for perfection.

Questions. I am getting conflicting advice from various developers. One says, do nothing, the sites are OK are they are; another said to use a WordPress mobile plugin. A third said, do NOT use a mobile plugin, and he wrote a simple mobile version – this may or may not be installed on the livenowlovenow site by the time you read this.

So I’m very confused – do something or do nothing and if something, what? –
clarification most eagerly sought!

Kind regards

Andy