Addressing your important point about whether you have to declare they declined to offer you insurance, just because they decided not to offer cover does not reflect adversely on you. Reading your blog, iprotect were clearly non-specific and it may have been any number of reasons completely unconnected with you or your application.
There are some technical considerations, such as some underwriters not wanting to insure too many people in the same postcode to spread the risk of unemployment clusters around specific employers/industries. There is no suggestion of any non-disclosure on your behalf, place your business with another company without hesitation.
Note: This post has been moderated. Please ensure you read the Moneysupermarket.com User Community Standards and Terms of Service before posting. Thanks.