Hi guys. I am starting a data warehousing for my company. 

However, I have doubts to whether I am going down the right path. So here is the scenario, so I hope you guys can advise. 

My company has loads of data for many years, so accessing the data via normal sql queries is resulting in long time retrieval. Hence my senior manager suggested using the data warehousing to store the historical data. The transactional data is stored in the normal relational DBs, and will be bulk loaded to the warehouse daily.  With that, the analysis and reporting tools can be used to generate the queried information.

I got a few queries on this. Apologies if they sound stupid. I have been reading a lot of concepts, but not so much of the implementation... 

Q: With data warehousing, I will no longer be able to write my customized queries in SQL since all the reporting tools will take care of them. True?
Q: Are all reporting tools accessing the database directly or can I use JNDI?
Q: What about the latest data that might not have been exported to the warehouse (It is stored in the ODS for quick aggregation yes, but what if I need to converge the data with that of the warehouse? Is it possible?)

Thanks a lot in advance!