yup it's a just depends question. My view is that you do what is best to achieve the end result from your database/application.

As an example I had a client where one of the DW loads ran for very many hours which meant reports were not ready early enough in the day. ( obviously I'm simplyfing this explanation ) I suggested they apply some indexes - "oh we don't want to do that, indexes will slow the data load" - well yes maybe but they'd speed up the next part - so I added the indexes and it took several hours off the overall process and reports were actually ready before office opened.

so what I'm saying is you do what you think is best - as for more indexes than data - yup in many databases/applications key tables have more used space for indexes than data. In fact if I look at one of my main production systems the indexes take more space than the data.

Hope this helps as I think you're going down the right path - btw suggested indexes aren't always 100% take the suggestions as just that and double check yourself if you are able.