I'd think carefully about the oiling - boats don't for various reasons. The primary one is that you lose grip, and that won't worry you, but the other main one is that it seems to attract fungal-type growth. I'm sure that someone should write a book on the subject, but once the deck is nice and flat a scraper (usually just a strip of steel with a burr left on it) used to be the way to keep it looking good, but more recently a green scourer pad ACROSS the grain is reckoned to be the way to go. Then chemically, different flavours of Boracol are touted, but the one manufacturer that seem to be the gold standard are Wessex,
http://www.teakcleaner.co.uk/index.php.
I've never owned a boat with a completely wooden deck, but used to work for a yachtbuilder whose boats nearly all had them, and the general feeling is that they're lovely when freshened up, but all accept that a bit of greying is inevitable before the season is over. It's just the way boats are. I see that yours is nearly always under cover in your pics, and that will delay the greying (oxidation I think) enormously.