We've both had our say in tons of speculation, but in lore, if you don't know for sure, for speculate till everyone beleives you're correct.
If Helseth is able to pull Morrowind out of the civil war intact, without permanent damage to her, then his objectives will come to fruition. However, it isn't the mark of a good leader that brings his country into Civil war without exploring every other course of action. Talk all you want about Abraham Lincoln, he however wasn't a puppet of an outside empire. I don't beleive that Helseth did explore every other possible action, I see rather that he saw civil war as a way to strengthen his own power, at the expense of the lives of many Dunmer, at the expense of the unity of his nation and at the expense of the trust in him and his Throne.
Right now, Helseth seems the best Morrowind could wish for. Indoril and Redoran were stuck in the past and not even the Nerevarine could have persuaded them to change with the times. If presuasion doesn't work than war seems the only option.
Helseth may be only acting out of self-interest, but his interests ironically coincide with what is probably best for Morrowind.
The interests of the Hlaalu, like that of the Temple, are inexplicably tied to the the events of previous eras. The Third Era has passed, and so I guess so will the interests of such oulander dominated structures such as the Hlaalu and it's imperial based ascendancy over the Dunmer.
What you said about Tribunal and it's aftermath is true however, Helseth tried to kill you and so did Almalexia, but you kill Almalexia and not Helseth. Pfft, is all I can say really. Still, you're of the opinion that Helseth is the "best for Morrowind"; this is ultimately, a Cyrodiilic-centric viewpoint. I see, and I contend that a leader "best for Morrowind" would be Morrowind-Centric. A leader is who is able to rule Morrowind without the aid of the empire or it's legions.