Here is one reference from Śrīmad-Bhāgavatam (Bhāgavata Purāṇa) 5.25 - 5.29:
tāmasād api bhūtāder vikurvāṇād abhūn nabhaḥ
tasya mātrā guṇaḥ śabdo liṅgaṁ yad draṣṭṛ-dṛśyayoḥ ||25||
From the darkness of false ego, the first of the five elements, namely the sky, is generated. Its subtle form is the quality of sound, exactly as the seer is in ...
Is there any scriptural ( Vedic or Puranic ) reference for all matter coming from Akasha and Prana?
Yes, the Taittiriya Upanishad says all elements come from ether:
tasmAdvA etasmAdAtmana AkAshassambhUtah | AkAshAdvAyUh | VAyuragnih | AgnerApah | adbhyah prithvi | prithivyA oshadhayah | oshadhIbhyo'nnam | annAt purushah
From that Brahman sprang ...
Manusmriti 10.95 says
जीवेदेतेन राजन्यः सर्वेणाप्यनयं गतः ।
न त्वेव ज्यायंसीं वृत्तिमभिमन्येत कर्हि चित् ॥ ९५ ॥
jīvedetena rājanyaḥ sarveṇāpyanayaṃ gataḥ |
na tveva jyāyaṃsīṃ vṛttimabhimanyeta karhi cit || 95 ||
The Kṣatriya, fallen in adverse circumstances, shall >subsist by means of all this; but he shall never think of >arrogating to ...
Yes, Danu was the mother of Danavas.
In Rig Veda I.32.9 Danu was mentioned as the mother of Vritra, whom Indra killed.
Then humbled was the strength of Vṛtra's mother: Indra hath cast his
deadly bolt against her. The mother was above, the son was under and
like a cow beside her calf lay Danu.