One inexpensive hotel and a youth hostel in Yangshuo. No accommodations in between. Camping does not exist in China. This is an unusual tour since you get to enjoy incredible mountain scenery from a table-flat valley. There may be an occasional slope, but nothing serious enough to require a multi-speed bike.
Road conditions can vary considerably.
It is mostly good pavement, but you may encounter extended stretches of construction where you need to deal with dirt or rough gravel. Road signs are usually in Chinese only. This is no problem since you are always following the main road and it doesn't make any turns. It is best not to drink unboiled water. In China, your hotel always provides you with a thermos of boiled water for tea.