Gooseneck.

Try and find a fitting that has a male part attached to the mast and then a socket in the boom. Lay up a composite socket (wrap the gooseneck fitting in tape and use it as the mould and then bond it into the end of the boom.

Outhaul.

Cut a "V" groove in the back end off the boom. depending on thewall thickness of the tube you might want to build it up a bit. Tie a line onto the clue and put a couple of knots in the rpoe to put in the groove.

As you said a webbing loop for the clew.

Job done.