it wont start another cycle( if anything a bacteria bloom for maybe 48 hours). believe me. Ive been using sand for years and swap back and forth a few times a year.
All the fish you have will be fine.( what kinds I forgot)
Dk, Ive cycled 4 tanks with angels AND neons. as long as you just let things be for atleast a month it will be fine.
Sand is a PITA to keep clean, get some malaysian trumpet snails( I got some PM me) to keep the sand turned and cleaned, do not go more then 2" deep at the absolute most no need to go deeper then that, it only creates headaches and that measurement is off a 55g,.