The stela of Mesha is hard to use, especially for dates : it was found outside its contexts and any datations is hasardous as best.
Regarding the "David" that exist on this same stela, it's an explanation but as the inscription wasn't preserved, it's an open field for alternative theories.
For the Tel Dan one, there's theory to understand the "David's[...]" as other meaning. Because it's not written in the classical form, it's maybe not "House" but "City".
It would be about the "City of David", Jerusalem, in this explanation.
Concerning the datation, it's sometimes considered as more recent date, between -800 and -730's.
I'm not saying that isn't acceptable as proofs for Israel and Juda existence, just that we have to be very cautious about the datations and formulas.
Of course, we can only agree on the existence of two (maybe a little more) semi-tribal kingdoms of the Hebrews in Palestine. What's is debatable is their extent, their datation and their relative independence.
Let's see the first post.
"What would be the consequences if the Ancient Israel Kingdom remained united after Solomon's death? How long an independent and united Israeli kingdom would survive?"
An UNITED kingdom, after SOLOMON's death that remain UNITED and INDEPENDENT from Sinai to Mesopotamia is nothing but ASB, as it's doomed by archeological proofs.