Quote - Is it just me, or is this piece absolutely RIDDLED with poor grammar

The linguist in me is quite interested to know what you're considering to be poor grammar.

Quote - But take note that it is "BBC" so some words like "customise" is actually spelled correctly, as that's how Britain and Canada spells it.  In the USA it has a Z instead of an S.

It's not quite as straightforward as "USA = z, UK = s".
Traditionally, if you were educated at Oxford University, you'd use "z" for words that came directly from Greek, and "s" for words that came via French. The OED (and its smaller versions) usually offers the "z" version as being the first choice where this rule applies.