Submetering of each ECM

Under Option D you need to calibrate the entire energy model. You are not evaluating ECMs in isolation, that is Option B. However this option rarely applies to new construction since it is not appropriate for projects with interactive ECMs. So you need to either measure or be able to derive every major energy end use.

I am not going to be able to tell you what you should submeter as I am not familiar with the project. You will need to answer this question for yourself relative to each end use - does this measurement give me the data I need to calibrate my energy model? Whether you submeter or not is generally a question of the efficiency of implementing the plan. Submetering generally reduces the time you have to spend in the building gathering data by hand so it is often more efficient to gather data this way but that must be weighed against the cost of the submetering.

In general what you propose would potentially get you the cooling and some or all of the pump energy. Some modeling software separates the cooling tower end use from the chiller so you may need to somehow gets an idea of the relative energy use of each. Figure a way to break out the pumps from the total and those end uses might be covered. For example, if the pumps are variable speed then the controlled can often be programmed to gather the pump data needed to determine energy use.

Domestic hot water in a hotel is generally a major energy user. Anything over say 5% of the total energy use would be major in my opinion.