Hello Majin_Vegeta_2028,
DO! use distilled water not tap water,Tap water has bleach, minerals,salts and sometimes fluoride.
Take yourself a wash rag and wet it to the point of being damp not dripping and lay it on the paper for a min or two and check it to see if it comes free of the cel.
On cels with lots of small hair tips rip the paper up the mid-line of the face and pull the paper to the outside edge along the hair tip until it comes free,don't start at the tips and go to the face,This will help to not pull off the hair tips.
The mold issue can be removed by keeping the cel out overnight to dry fully before you rebag it,Paint sucks up some water and this needs to dry before you store it.
If your stuck paper has colored pencil marks on it be careful and remove it fast after you wet it because the colored inks can bleed into your cels paint and mess it up real bad and this can not be removed from the cels.
If you have Cels that are stuck together and they have a paper backing that is stuck to them try not to let the water get between the cels as you remove the paper, this will save you a long time to dry after you remove the paper.Try folding the edges of the paper back a little bit from the edge to help keep the water were you want it and not inbetween the cels.
I hope this helps out some.
Roy

(DBA)Backlotanimation