It’s not empty, it’s just that Amaze can’t list contents in /data without root permissions. Check Amaze settings and enable “Root explorer”
Understandable. If you’re totally pissed of and you’re going to take a break from FP2 (like I did refurbishing a Moto G in the past), I suggest looking for a second-hand phone with official LineageOS support, and wait until FP2 gets official status as well to change again to it. Otherwise, you can try the unofficial LineageOS community build (which may have minimal bugs but seems stable enough).
With any of those options, you would have less issues than with FP Open, and having very great developers actively working on them is a plus.