[Advaita-l] A question on Sanskrit usage

[V Subrahmanian]

Namaste.

Here are a few usages in the panchami:

(गृहात् ) गृहतः आगत्य कार्यालयं गच्छति  - Having come from home he goes to
the office.
(शालायाः) शालातः निःसृत्य क्रिडार्थं व्रजति - Exiting from the school he
goes for playing.
(आत्मनः) आत्मतः प्राणः, आत्मतः.... - This is a Shruti passage saying 'from
Atman PrAna originated, etc.'
(सूत्रात्)    सूत्रतः उद्धृतपदानि एतानि - These are words taken out from the
sUtra.
(तत्त्वात् )  तत्त्वतो भिन्नाः ...- Essentially distinct/different

In the above sentences the panchami is used in a way different from the
conventional usages shown in brackets.  Are such usages perfectly correct?
Is there any rule governing such usages?  Are there exceptions or is it that
one can use them everywhere?

Though this is not strictly Advaita-specific, I request learned members to
clarify.

Regards,
subrahmanian.v