alerts are saved remotely https://dashboard.twitch.tv/stream-alerts
#lost everything
bitter oasis
the others are saved locally. check your backups if you have one
if you format your pc, or having a new pc, you will have to copy your old profiles over
uninstall will wipe that data... not sure about reinstall
%APPDATA%\Twitch Studio\
and layouts.json you should backup at least
your images and stuff are probably in another location
just bring them back and position them again
you can always start with the default or find a stock overlay from the internet