Hi,
Unfortunately, both the requirements are not possible. You cannot manipulate BEx-->Open directing to your own choice. You cannot remove Infoareas which is very essential for your developments.
There was a big discussion happened on this recently on SCN. The ultimate conclusion is a big NO.
Refer this discussion: http://scn.sap.com/thread/3378464
You can activate BEx history( Entries only in the History folder) through RS_PERS_ACTIVATE t-code. You cannot vanish any Folder like History, Roles, Favorites, Infoarea..
Regards,
Suman