Shatanand was the son of Sage Gautam and Ahalya and not Indra. In Balakand Sage 51 Verse 1 and 2, he was told to be the 'eldest' son of Sage Gautam and Ahalya.
Sarga 51 Verse 1 and 2
तस्य तत् वचनम् श्रुत्वा विश्वामित्रस्य धीमतः |
हृष्ट रोमा महातेजाः शताअनन्दो महातपाः || १-५१-१
गौतमस्य सुतो ज्येष्ठः तपसा द्योतित प्रभः |
As per PADMA-PURANA: SRSTIKHANDA: Chapter 54,
4-5a. Suresa (i.e. Indra) had vaginal marks (on his body)
because of having outraged Ahalya only. Then again, due to the
favour of Goddess (Indraksi / Indrakshi), he, became well known as
Sahasraksa / Sahasraksha (one having a thousand eyes). This is known in the
entire mobile and immobile world.
No, the particular verse you are talking about of Uttara Kanda is not present in critical edition of Valmiki Ramayana. The exact verse found in other versions is Valmiki Ramayana, Uttara Kanda, Chapter 30, Verse 39 and 40
तदाप्रभृति भूयिष्ठं प्रजा रूपसमन्विता।
सा तं प्रसादयामास महर्षि गौतमं तदा ।।३९।।
अज्ञानाद्धर्षिता विप्र त्वद्रूपेण दिवौकसा।
Is 'Ahalyā' the real name of Gautama's wife or is it an acquired name?
Yes, this is her birth/real name which was given by Lord Brahma. This is given in this chapter of UTTARA KANDA of Valmiki Ramayana:
[Lord Brahma to Indra]: O Chief of the immortals! O lord !, some
creatures were created by me by dint of my understanding they were all
of the same ...
I am not sure what you call the Critical Edition of Rāmāyaṇa but it is not from those 5 Sargas which are believed to be interpolated. This shloka can be found in 30th Sarga (this number is after removing 5 interpolated Sargas else it would be 35th Sarga) of UTTARA KANDA of Valmiki Ramayana:
As shloka clearly says that these lines were said by Ahalya to ...
Ran into this question from a different discussion you are having elsewhere.
Shri Madhvacharya says the following in his anuvyAkhyaana --
na chetanavikAraH syAd.h yatra kvApi hyachetanam |
nAchetanavikAro.api chetanaH syAt kadAchana
In simple terms, a chetana never morphs to become an achetana i.e. jaDa and vice-versa. This is in the fourth pada of first ...