InsuredHoliday.com
This would imply you are buying "a holiday that is insured", as opposed to something like "InsureYourHoliday.com" or "HolidayInsurance.com" where you would already have a holiday (your primary purchase) that you are insuring (secondary).
The commercial aspect and profit of a holiday is the flights, hotels, etc. While the insurance is quite a profitable thing in terms of percentage/markup, the actual total monetary gain is not high enough to warrant selling holidays off the back of insurance.
You buy a holiday and insure it ("HolidayInsurance.com") not buy an "InsureHoliday.com".
I'm afraid I'd say reg fee.
RevisedMortgage.com
I cannot see how this could be used. Banks and solicitors (lawyers) etc deal with such things, who have their own websites and this is one of various services they offer. So is this somewhere you log in to and request or view a change in your mortgage? I would only want to deal direct with the financial company who I have the mortgage with, not some 3rd party website, even if tied to the bank somehow.
And there is no benefit in it either. If Banks where to somehow tie your mortgage in to this website it would surely be much more work for them in terms of API security and how the 3rd party handled their customer's data, than just having it all under their own secured website which adheres to industry requirements, SLAs, etc.
Reg fee