fix 4626:c26b4df9fc90 (#703911): use can't rely on peid since it's not an actual eid when we're creating the parent entity

[form fields] nicer behaviour of the password field: don't put internal field value on edition (triggering validation error if one validation without removing the value, due to confirmation mismatch), and don't show the field as required in such case

minor cleanup: don't use builtin 'id' as variable name