On the subject of the possible death of the party, I find it hard to have sympathy for the more moderate side of the party with their arguments that they have to present an opposition to a Tory majority when they've had ample chances to introduce, or influence, a move to PR or a different form of voting which would've helped stop Tory majorities.
Blair/Brown were in power for 13 years, and won three elections. Scotland and Wales were given devolution with different voting systems (mainly to stop nationalists gaining majorities), and yet neither made a move towards a new PR system for UK elections. Doing so would've probably stopped any future majorities, and could've even allowed any eventual split within the party to occur more amicably, with the knowledge that the two forces could work together on coalition bases if that was required. They didn't though...because they were presumably more concerned with keeping power for themselves than denying it to the Tories.
Even after that, Labour could've fully committed to supporting AV in the referendum a few years back...which would've perhaps helped slightly, even if it wasn't an effective as PR, in denying Tory majorities. Again though...they didn't. Another chance to deny future Tory majorities blown.
Due to that I find it quite difficult to sympathise or empathise with the admittedly understandable concerns. I get that a lot of people here just genuinely want a credible alternative to the Tories, but the parties actions since the Blair era don't indicate that...it indicates a party who were more concerned with power for themselves than preventing the Tories from gaining power. That short-sightedness, and a lack of foresight from anyone within the party that future divisions or potential Tory dominance could be costly, has harmed them greatly. And only the party can be blamed for that. They had their chance, and they blew it.