If I were to start over playing raft, I would...
1. Gather Materials
2. Craft Building Hammer
3. Continuously Increase Size Of Raft
4. Craft Water Purifier
5. Craft Cup
6. Craft Grill
7. Craft Fishing Rod
8. Craft Spear
9. Craft Bed
10. Craft Paddle
The best tool to make for survival would have to be the building hammer. Without it the sharks would eat your entire raft and then you, and you wouldn't have any space for crafting things.
The best feature of my raft is the space that I have created by keeping items close together and by using tables and shelves to conserve space.