XML Schema generation differences found on upgrade

[atingley]

I have recently updated my EA version to 6.1 (from 4.51).  I found the following differences in generating an XML schema:

1. <xs:annotation> tags are inserted for all the Notes on model elements

2. complexType definitions used to refer to an attributeGroup for its associated attributes; now the attributes are in-line

3. it appears the attributes are alphabetically ordered (instead of the order they appear in the model)

4. attributes that have no "use" tagged value (in the model) are generated with "use='required'" values; shouldn't these default to "use='optional'"?

5. elements with no internal structure (no contained elements), only attributes, are generated with an empty <sequence/> tag

Are there any settings one can use to change this (and is (4) a bug?)

Thanks.