I think England does need its own Parliament. At the very least it needs decisions that affect England alone to be taken by representatives of England alone. When Scotland, wales and Ireland did not have parliaments and assemblies we were all in the same position but now we are not. Why do I want 59 MPs from Scotland voting on English only matters? I do not want a single non English MP to have a say in English matters. Do you think the Scots would have a token 10 English MPs voting on their internal affairs - I think not.
Parliament has changed massively in the last 25 years and only the English are left without sole control of their own affairs. Why keep it that way at a time when you are sorting out the other problems.
Why on earrth does a federal structure need units of the same size? Have you looked at America?
4 elected bodies each dealing with their own affairs makes abundant sense. Each can have a degree of tax control to handle health, education, police etc. They can set prescrition charges, the extent to which they farm out work to private bodies rather than state run ones, the level of benefits they provide and indeed which benefits. It gives flexibility for when one of the "states" has higher or lower unemployment and so on. MAtters that need to be the samefor all of the constituent elements - defence is one of course as are foreign affairs, diplomatic relations and so on are then paid for out of federal taxation.
You cannot deny the English a parliament because you want Scottish Labour MPs to control the English. England would have to come to terms with the parties it wants to have - and I suspect there will be less Tory and Labour than you might think. For a start I owuld advocate PR rather than first past the post in order to give valid representation to Greens and others and also to ensure greater "consensus" government.