Hi Martin,
Super simple approach to your gooseneck could be tiny screw in hooks and eyes from the local DIY emporium,
epoxy short lengths of dowel into the mast and boom to give the screw something to bite into, popular on toy yachts etc.
Or 'binding' a fitting (ali right angle with a bolt pivot through it etc) to the mast with strong thread,
apply a coating of epoxy or varnish to beef it up and protect it - simple method of attaching items.
I have taken this a stage further using ball links for the gooseneck and kicker,
both are screwed into threaded holes in a piece of ali bar, this is then bound to the mast and filled and painted over,
see below photo - might spark off an idea !
Attaching lines to booms etc ? have a look at pictures of the smaller model yachts RG65 & 1 metres etc,
tight fitting rubber grommets pushed onto the boom with the line tied through or around the grommet gives an attachment,
then sliding the grommet along the boom gives sail adjustment.
Fishing tackle shops can also be a good source of model yacht fittings -
the little wire clips in the photo are fishing products I use to attach my lines etc, easily detachable for transport.
Hope this is food for thought and where's the action movie we are all itching to see !
regards Paul