1.No.Mahardasa results will depend on various factors.
Similarly,antardasa need not give same results,as mahardasa.
2.May or may not.
3.Being placed in 12th house is major point.It is bad.
It gives bad results.You have to do penance for two years,
to reduce severity.
See in google-kumrao99 penance method.
Moolatrikona is secondary point. firstname.lastname@example.org