Hi Sidharth,
Answer to your 1st point:
Two views -- ( Most Debated though 
)
View 1:
a) If you import the BW Cube/DSO using HANA "Import" wizard it helps you to to redeploy your "HANA Model" whenever you activate your BW Info cube.
b) Analytic Privileges in HANA can be directly mapped to "Analysis Authorizations" in BW.
Meaning HANA Views become a part of BW life cycle management.
View 2:
If you want to use the Active table of the DSO as some lookup in some other business logic, then it is better you directly model on top of this table.
Performance wise there may not be any deviations, only the management of this views are of concern here.
Answer to your 2nd point:
As i said it is "Technically Possible", we can create analytic view on the active table of a DSO.
It is just not an "Suggested" approach from SAP.
Do have a look on the below blog:
HANA-Native Reporting on BW Data in #BWonHANA &... | SAP HANA
Regards,
Krishna Tangudu