Two Days and One Night in Liuzhou
Worth the visit—Liuzhou is great, with beautiful scenery and delicious food. Two days and one night is enough. I recommend staying near Wuxing Street or Qingyun Market for easy access to food and drink. I personally stayed at the Vienna International Hotel; it's a short walk to both places, clean, and with good air conditioning.
Longtan Park around 7 AM is not crowded, with nice scenery.
For the night cruise, you can buy tickets online or on site. Don't believe that you can only board after 7 PM—everyone arrives early, and if you don't show up early, you won't get good seats.
Yaobu Ancient Town—if you've already done the night cruise and aren't into travel photography, you can skip it.
The music fountain is packed with people; the night cruise stops nearby to watch one song.
However, April in Liuzhou is already super sweltering—pure sauna weather—yet most places here don't turn on air conditioning. Also, Guangxi has a festival called Sanyuesan (March 3rd), which I happened to encounter. It felt like a hundred million people were there.