Your data won't be lost as long as you don't wipe a single thing. Use custom recovery such twrp to flash your rom package, but don't forget to check its md5 checksum firsr
I like this custom ROM you provide, you rock guys!
I would to report a minor bug, there is no 4G preffered in preffered network setting (I'm using Libra) as showed
I hope you fix this in future updates,
Thank you!