It would have been a minority government, I doubt it would have lasted 12 months
It would also have involved the Lib Dems allowing Brown to continue as PM - as much as we hate the Tories now, folks have to remember that Brown was extremely unpopular.
Kennedy - indeed, a lot of the party, probably the majority - would have preferred to work with Labour. We have vastly more in common with Labour than we do the Tories. But, ultimately, Cameron and Clegg was a more sane paring than Clegg and Brown.
If Brown had held on to a few more seats, then a Lab/Lib/SNP government could have happened.
Again, the 2015 election was a story of two halves. In Scotland, Labour were thrown out. In England, the Lib Dems were thrown out. It was thanks to the latter that Cameron got his majority.
By accepting the "Lib Dems were the enablers" narrative, you're forgetting that what enabled Cameron in the end was people NOT voting Lib Dem, not people voting for them.
In 2010, had the 1st TV debate been held one week before polling day instead of a few weeks before, you'd have had Clegg as PM.
In 2015, had Clegg stood down as Lib Dem leader and/or the public in Tory-Lib Dem marginals had not decided to punish the Lib Dems, then you'd not have had Brexit.
The same is true of voting for Labour, of course - had Labour run better campaigns in 2010 and 2015, we'd be in vastly different situations right now.