Answers for all the questions are numbered accordingly.

 1. Yes, if possible in tree structure, so that the search is very easy.
   Infact, all the decentralized cloud are transparent as well.

 2. Ethereum vs EOS
     - Ethereum has free account creation, but EOS has some cost which mainly depends on RAM price.
     - gas price during each transaction. But EOS has feeless transactions.
     - Ethereum currently can't segregate actions of different contracts, which EOS very easily does. Moreover, there are 2 types of actions on EOS - inline (validated on network at that time) and deferred (set a time on its execution).
     - Currently, Ethereum can't process dApps at the required speed, but on EOS there are already few games launched - dice, eos knights, etc. which are running very smoothly without delay.

 3. Although EOS architecture is completely different than Ethereum. But, definitely you can run the search for any kind of data.