OK - fair 'nuff - but really really need a decent native English speaker to triple check it.
Too complex. The "who pays who" schematic on page 4? was scary. You need consistency in naming people (National Grid not SO etc). And quite frankly - I don't care who pays who anyway, as long as I get my cheque...

Mozilla do
http://www.seamonkey-project.org/ as a free web editor with spell checker.