Tony, firstly I think it is fair to say that the Price List is not the place to include those statements, they should be under the additional conditions in the Contract Data, having said that they are in the contract and it is clearly stated that the Contractor has signed up to them. The answer to your question is yes the Employer can impose the exclusion to claim loss of profit because the NEC conditions do not allow for it either, however there are issues with the drafting.
Firstly, any omission of items or Areas [sic] of work will require an instruction from the Employer changing the Works Information which will result in a CE under clause 60.1(1).
Secondly, they refer to the ‘full cost’ of the item and not the Price, Price is defined term (11.2(10)) and that would have meant the amount stated in the Price column, instead reference to cost must be taken to mean Defined Cost which means the assessment would be under clause 63.2.
The importance of clause 63.2 is that it assesses the changes to the Prices but ignores the Prices in doing so, instead it forecasts the effect of the CE upon the Defined Cost plus the percentage for overheads and profit.
So if an item in the Price List has a Price of £100 but the forecast effect of the omission is Defined Cost £80, oh&p 10% = £88; the changes to the Price is -£88. The difference between the original Price and the assessment of DC is kept by the Contractor, e.g. £12. People should also realise that this could go the other way, the forecast DC + oh/p could exceed the Price in which case there would be a greater reduction than the Price in the Price List.
With regards to the setting of an earlier Completion Date, this is unusual and usually not provided for within NEC contracts, the wording of the delay assessment clause 63.4 refers only to Completion being delayed. There is a clear contradiction here between clause 63.4 and the statement in the Price List and it maybe here that a condition of contract is preferred over a statement in the pricing preamble but I cannot be definitive on that; one for the lawyers.
I think this is a good example of why contracts need to be drafted so carefully, the amendor needs to know the contract and use the language of the contract, otherwise they are in danger of introducing ambiguity and/or inconsistencies which should be read against them under the law of contra proferentem.
That’s my view on it, happy to discuss.