Nice little snake you got there.
Antaresia in general warm up with age, not handling. They can be defensively nippy as babies and lose that as they gain some size and settle in.
75 is okay for an ambient but a little higher would not hurt. May be hard to raise the ambient in that small container without throwing some other parameters off....there are some ways you can bump the ambient up a few degrees...PM me for more details if interested.
Childreni like to climb and are an animal that - while capable of existing in a tub - really show much more of the natural behavior in an environment where they can stretch their legs (in a manner of speaking). Unlike ball pythons, once acclimated they can show a tendency to spend less and less time in their hides.