The practice of Ishaarah among ‘Ulamaa does exist (i.e. alluding to inner meanings) but was never meant to replace proper formal Tafseer (unlike Batini groups, where for example “establish prayer” may mean only to vaguely remember God without any formal prayer).
What does the word ‘Allah’ describe? One explanation given by our scholars: it is the proper name for the Entity of the Necessary Existent. Note that we don’t say ‘define’, since Allah cannot be defined.
The Qur’an could only have been revealed on the heart of Prophet Muhammad (ﷺ); even mountains would have crumbled if the Qur’an had been revealed to them.
(As was mentioned) The Basmalah is an ontological statement: That all reality exists only in the name of and through Allah. The Basmalah teaches us metaphysics as well, in its ordering Bi Ism and Allah, that by Allah’s creating of contingent existents, the names of Allah become evident in creation.
As was mentioned: The epitome of Divine Justice is not manifested in this world, rather it is manifested in the Hereafter; this is an important point of Islamic belief.
The scholars sometimes allude to the concept of ‘Ilm Ladunni: this is Knowledge given by Allah to those whom He wills, without them ever having studied these matters.
As far as Muslim theologians are concerned, the evidences and proofs of Islam are administered like a ‘buzzsaw’ – sounds harsh, but as an example, what is true necessarily is what it is and this is the end of the story, no emotional rants or pleas are accepted. This is why spirituality is different, and even more effective for many people, since in a class of spirituality the words can be used in other than their strict theological definitions and can have an effect on the hearts of a different sort of people.