It's hard to think of a hint for this kind of puzzle, but here are some realisations I had while solving that might be helpful 🙂 (ROT13)
1. Rirel fcver fubhyq or cneg bs ng yrnfg 2 yvarf.
2. Vs n fcver vf bayl cneg bs bar yvar, gel fuvsgvat vg nybat gung yvar
3. Gurer ner zhygvcyr fbyhgvbaf, fb gurer zvtug or n fgne-funcrq bar, ohg nyy gur barf V sbhaq ner abg fgne-funcrq.
Biggish spoiler:
4. Fcverf ercerfrag gur vagrefrpgvba bs yvarf. Cnenyyry yvarf qb abg vagrefrpg, fb rnpu yvar jvyy unir n qvssrerag fybcr.