Just like any other company.
I would start with google analytics. If you configure it correctly you can get quite far down the line for free. Once you start seeing revenue and need more detail you can move over to one of the more premium or paid for systems.
It depends on what you mean by "Visualized Data." Do decision makers use graphs, charts, dashboards, etc? Yes of course. Are there some visualizations that wouldn't be of any value to a decision maker whatsoever? Also yes of course. You can't show me a word cloud if I work as a portfolio manag...
Parse is indeed one of the best for user accounts, IAP tracking, custom push, analytics and user data sets. You can watch this video http://www.youtube.com/watch?v=E_0llIdtYNA on Youtube for some basic understanding of the Parse platform.
This is difficult to answer because you haven't given us much to go on. What type of hardware are they building, and how big and fast do they plan to grow? It really doesn't sound like they have a growth strategy in place yet, so my guess is you would need to create that for them, right? If that...