Differences between PowerBI and Stream Analytics for real-time dashboard

Hi,

I'm using PowerBI online with a profesionnal account. I read excellent articles about handling powerBI datasets through an API, that's awesome!

I need to insert data in a daily temp dataset to have dashboard in (real) real time (eg : Number of visits of the last 24h).However, I'm wondering about differences between using API vs using EventHub + Stream Analytics to insert the data in dataset in real-time.

I have several questions :
1/ What is the storage of the data uploaded in a dataset through the API ? Are they stored in a Azure SQL Database ?
2/ And what about the persitancy of these data ? Is there a scheduled drop of these data or these data are persistant ?
3/ Is there any limit on the API ? I hope the limits raised in the following post have been resolved (cf http://community.powerbi.com/t5/Service/Limits-when-using-Power-BI-REST-API-and-or-Azure-Stream/m-p/6367#M3242)

Thanks !

Romain.