Reading #6, the Byz. reading, could be read as "who were both lamenting and mourning him." Clarity is added that the women (professional or customary social mourners?) were the ones doing both acts of lamenting him and singing/wailing a funeral dirge for him (and not the large multitude of the people, although such an understanding would be awkward anyway). Some like constructions of "KAI participle KAI participle" are found in Mt. 4:24; Mk. 1:40, 5:38; Acts 3:8, 13:3, 22:20; 1 Thes. 2:12; and Heb. 11:13, so adding the first KAI is not unusual or laden with difficulty.
With #4, the confusion of the sounds of AI and E that became more common in NT MSS in the later Byzantine period is highlighted, which could be behind the variant itself to some extent since the difference is really the K in the three sounds of hAI, KAI, and E(KOPTONTO).
Reading #5 shows where at least a couple of scribes in a later period went with only KAI and not the relative pronoun, which causes me to wonder if the rough breathing sound wasn't somehow confused with the K sound along the way, but I don't have and am not aware of any data to back up this type of confusion.
Since "hAI" is in most of the texts, this pronoun is not the major question (as Wieland noted), but rather the addition of the KAI is the real difficulty. The repetition of hAI and then KAI would seem to have been hard to miss in so many different witnesses with the variety that they represent in the textual streams. Instead of parablepsis, I would think that the omission of KAI would likely have to be credited to the elimination of an unneeded word, a grammatical correction in other words. But the Western witnesses (D and several Old Latin mss) speak against this option. On the other hand, KAI could have been added for both clarity and as a fairly common way to unite the two participles with a common subject. Due to the strong and early external evidence for hAI and especially against KAI (adding 01 and L to the evidence against KAI), I would think that the addition of KAI would be most likely.
Another hypothetical explanation (since I don't know of any data for confusing hAI with KAI) would be that the confusion of hAI with KAI would explain the shift to KAI, which would then occasion the shift to hAI KAI due to conflation.
Director of the Center for New Testament Textual Studies
Landrum P. Leavell, II, Professor of New Testament and Greek
New Orleans Baptist Theological Seminary