We stayed at Breakas last September and had no hassle getting back there into the later hours. The buses cruise the main drag looking for customers, and at quieter times will actually slow down and ask you do you need a bus. As do the taxis, so just remember the bus will cost 300 Vatu per person, 600 Vatu for 2, so if the taxi says he'll take you for 1000, and you are ok with A$4 or so more, just take the taxi.
The reason they suggest reef shoes for Mele Cascades is there are parts of the walk through the water over quite slippery rocks. While there is a guide rope to hang onto, shoes with grip help. $10 at the shops above will have you in these high fashion items haha. (They are crap looking)
Have a great time in Vanuatu, Breakas is a great spot. Don't forget to go straight to Au Bon Marche at Numbatu and stock up on nibbles and drinks, ie beer, water, mixers, so you don't have to rely on the quite expensive offerings at the Resort.
Most importantly, come back and tell us how it all went!