I see no reason, mr2mk1g, why you should not establish a neckline now, you certainly have enough stubble and I think you will find that it will make your burgeoning beard look better defined and more professional. The received wisdom that necklines should only be defined after quite a lengthy growing period seems, as far as I can ascertain, to originate from a US based website; but my observation of what most guys in London are doing when they first grow their beards, and what I did myself long before there was anyone around to give me advice, is that here in UK necklines tend to be established sooner rather than later, and in this we tend to differ from our American cousins. Of course, if you are going for the "natural" look or intending to grow a long beard the question of a neckline is irrelevant, but for those of us who work in an office environment and have to observe certain standards of dress, a neat and well edged beard is, I would venture to suggest, essential if our beards are to gain acceptance. I certainly found it so.

As for trimming, I think that you should wait for at least another two weeks - possibly more - before you venture on that. Meanwhile if your moustache hairs grow over your lip and make you uncomfortable you can always snip them back to line up with the top of your upper lip. In fact IMHO that is pretty well all the trimming you ever need to give your 'tache if you like a fairly full one.

Judging by your pics I think you will probably need to trim your cheeks a bit later than when you first trim your goatee, but I believe that given time they too will fill in satisfactorily.

Keep growing. Stay bearded!

wulff