Fraud - Differentiating by degree?

The Telegraph carry the news that:

"MPs who have used taxpayers’ money to pay for “phantom” mortgages on their expenses should be investigated by the police and prosecuted, David Cameron says in an interview with The Daily Telegraph. "

For a while now I have thought that The Telegraph's coverage of the expenses story has been indiscriminate. We need to differentiate between:
1. MPs who have committed fraud - for example by claiming mortgage repayments on a mortgage that had already been repaid
2. MPs who have pushed the boundaries of House of Commons expenses versus tax law to the limits - for example those who have built property portfolios on the back of flipping so as to avoid Capital Gains Tax
3. MPs who have submitted expense claims that seem to have been based on falsehoods - for example every month claiming up to the no receipts required limit
4. MPs who have claimed or tried to claim for ridiculous items that should not be claimed for - for example moat cleaning, £2,000+ televisions etc.
5. MPs who have worked the system and so are guilty of no more than greed
6. MPs who have made only reasonable claims

The MPs who fall into category 1 need to be investigated and charged by the police, prosecuted and tried. All should be made to resign immediately if found guilty and receive no severance pay.
The MPs who fall into category 2 need to named, shamed and if not able to be prosecuted then to have the party whip withdrawn from them.
The MPs who fall into categories 3 and 4 should be made to face reselection by their constituency party ahead of the general election.
The MPs who fall into category 5 should consider themselves fortunate to have no action taken against them.
The MPs who fall into category 6 deserve no praise, they just did what they should have done.

Now to the future for MPs who have to resign or lose their seats. If they fall into categories 1-4 then they should not be considered for elevation to the House of Lords or for paid positions on Quangos or any position in Public "Service". They should find work in the private sector and learn what the real world id all about.