The rodent sizes vary a lot it is why I like to use weights. 10% is a normal meal and once a week is fine for a sub adult. Heck I feed adults once a week too just not always 10%. 100gm at a year seems fine to me my last snake that is just over a year is 900gm so not very far apart. It seems like everything you have said is normal what the heck are they saying? The FB page I belong to has some of the stupidest notions I have even heard of on it.