I agree - I am 100% positive that a full search is on the roadmap - its been requested by many. As for product heirachy - does collections within collections or articles within collections not work? I do know what you are saying... and can see HTML storefronts being on many people's feature lists. Be keen to know how far down the road map this is with Adobe, if at all, and if any customisation is possible outside of the portal.
I totally get the concept behind cards and layouts and the flexibility they offer. For some our customers however we need something far powerful like we built in the App "Knauf Infothek"(Only available in the german iOS and Playstores) according to their CD. For the guys at Conrad Caine who built the Siemens DPS App the new DPS could work but for Knauf with it's complex product hierarchy and multi-level-filter product search it is just not enough.
Hmmm, why would you need a custom storefront when DPS 2015 is totally customisable?
Yes, I know you'll say you want your own effects and animations in there - and I am sure cards and browse pages will support that soon enough - but the system is built to be completely original from one user to the next - (ie: no two DPS 2015 apps should ever be the same as previous, and the tools are far more flexible than stuffing a 20MB storefront into a DPS app that would need updating and no doubt fixing on a regular basis).