1. I am assuming you are refering to the Luck Pillar "Gui Hai" as opposed to "Gui Ren". The Water element is of course strengthened next year. However, the Wu would combine the Gui for the second time in your chart. I don't have your full chart, so I am guesstimating, that this should concern your health next year. Perhaps it's time to do a routine check up, particularly to 'heart' and 'eyes'. If not, it could also relate to the wellbeing of your Mom or an elderly lady.
2. Source of reference is Xie Ji Bian Fang Shu - The Book of Unifying Times and Discerning Dimensions (Qing Dynasty). I have also written a book called 'Dong Gong Date Selection' which is not available at the bookstores. This book has the charts for the subsequent years tabulated. If you are interested you may purchase a copy from my office.
Warm Regards, JY