Bash, Remove empty XML tags

I need some help a couple of questions, using bash tools

1. I want to remove empty xml tags from a file eg:

 <CreateOfficeCode>
      <OperatorId>ve</OperatorId>
      <OfficeCode>1234</OfficeCode>
      <CountryCodeLength>0</CountryCodeLength>
      <AreaCodeLength>3</AreaCodeLength>
      <Attributes></Attributes>
      <ChargeArea></ChargeArea>
 </CreateOfficeCode>

to become:

 <CreateOfficeCode>
      <OperatorId>ve</OperatorId>
      <OfficeCode>1234</OfficeCode>
      <CountryCodeLength>0</CountryCodeLength>
      <AreaCodeLength>3</AreaCodeLength>
 </CreateOfficeCode>

for this I have done so by this command

sed -i '/><\//d' file

which is not so strict, its more like a trick, something more appropriate would be to find the <pattern><\pattern> and remove it. Suggestion?

2. Second, how to go from:

 <CreateOfficeGroup>
       <CreateOfficeName>John<\CreateOfficeName>
       <CreateOfficeCode>
       </CreateOfficeCode>
 </CreateOfficeGroup>

to:

 <CreateOfficeGroup>
       <CreateOfficeName>John<\CreateOfficeName>
 </CreateOfficeGroup>

3. As a whole thing? from:

 <CreateOfficeGroup>
       <CreateOfficeName>John<\CreateOfficeName>
       <CreateOfficeCode>
            <OperatorId>ve</OperatorId>
            <OfficeCode>1234</OfficeCode>
            <CountryCodeLength>0</CountryCodeLength>
            <AreaCodeLength>3</AreaCodeLength>
            <Attributes></Attributes>
            <ChargeArea></ChargeArea>
       </CreateOfficeCode>
       <CreateOfficeSize>
            <Chairs></Chairs>
            <Tables></Tables>
       </CreateOfficeSize>
 </CreateOfficeGroup>

to:

 <CreateOfficeGroup>
       <CreateOfficeName>John<\CreateOfficeName>
       <CreateOfficeCode>
            <OperatorId>ve</OperatorId>
            <OfficeCode>1234</OfficeCode>
            <CountryCodeLength>0</CountryCodeLength>
            <AreaCodeLength>3</AreaCodeLength>
       </CreateOfficeCode>
 </CreateOfficeGroup>

Can you answer the questions as individuals? Thank you very much!