1-the scientist with judge said that the modifications were successfuly received by the quintet, it's just that sanji didn't show results as early as his siblings, even in a later flashback there were scientists suggesting that they should give sanji more time to manifest his abilities.
2-niji cared about reiju when she was about to be attacked by big mom. And niji and yonji cared about judge when big mom attacked him. Only ichiji was commented on by reiju to be horrid brother because he stayed focused on the misdion.
3- perospero said that the raid suit is memory armor, and we know it existed for 300 years and only give specific powers to specific individual, sanji mentioned that it can be redesigned so it's highly possible that judge modified it to enhance his children's super powers.
Judge never commented on DJ, he was more enterested in sanji using haki.
The swirly brows, DJ, and the ability to wear the raid suit that made his bidy feel weird and seemigly enhancing his DJ.