This might not even be a plot BUT...

Unless you count the fated Rockstar, through all my nine months (doesn't sound as long as it feels, wow!) I have never seen leadership change hands paws. How many lives do all these leaders have left? When do they lose them? When do they die? Why do leaders go so long without appointing deputies sometimes (sorry Breezestar), in disobedience to the warrior code? I know time is fluid on this site but it confuses me.

To put simply as possible, it's because we all have to deal with the scary place called the real world and because time consistency is an issue.

To put far more complicatedly...

First of all, most of us don't keep very good track of how many lives we have left, because it's actually really hard to lose lives in roleplay! In the book, leaders are constantly dying, because of disease, or starvation, or in the heat of battle...
In roleplay, it's a different story. We only get diseases or starvation in plots that happen maybe three or four times a year at most.
And it's bit annoying dying of greencough several times in a row. And as for battles... Well, WCC just doesn't have battles as often as it should. The only times it does is during camp raids, and those hardly happen at all anyways. (At least to everyone but SkyClan/ShadowClan ;_;)
It's pretty hard finding opportunities to die. Many leaders, when they finally pass on, often have 5 unexplained deaths... Just because there were nowhere to fit them into roleplay.

As for why leaders seem to lead so long, first of all, it's because of the strange perception of time that WCC has.
Think about it. The roleplay sticks to the seasons as the real year goes. So three in-real-life months of Leaf-bare/Winter, three in-real-life months of New-leaf/Spring... And it just keeps going. Even the gatherings happen once a month.
But time moves WAY faster for the cats. It takes one irl week to become an apprentice and one irl month to become a warrior. If you think about it, in roleplay, it takes over an entire year for a cat to grow from a kit to a warrior, and it can all be done before the next season even comes! It's an unspoken weird thing nobody talks about, but it certainly does make it seem like the leaders live a lot longer than they really do.

In reality though, nine irl months for a leader isn't really that long. We used to have a rule that leaders could only rule for nine irl months, but it didn't work out. Why? Because it simply wasn't necessary! Nine months after the rule was made, roleplayers were still happy with their leaders, the leaders were still taking good care of their clans, and felt like their cats still had so much more potential. And it didn't seem fair to force people to stop being leaders (which would require them to become elders and hardly used, or forced to be killed off.)
There isn't a limit on how long someone should be leader because why should you have to replace what isn't broken?
Although some of us like to push it. COUGH. FALCONSTAR.

As for why some leaders go without deputies, yes like my character Breezestar, it's because leaders have to take in-real-life considerations for deputy. They have to pick a good roleplayer, someone trustworthy, who the know will stay active and take care of their clan after their leader's death. And that can be a pretty difficult decision to make...
In character you have a lot of options, it's the out of character consequences that make it hard.

For example, like you pointed out, I (Breezestar) had Rockfall as my deputy because for a long time, I thought that it was a good choice. But you saw what happened. I tried to let Breezestar go and the newly named Rockstar killed himself shortly thereafter, leaving SkyClan with no leader - and no deputy either (probably because the options were almost nonexistant because the clan was so tiny at that point). It was because Rock left SkyClan leaderless that I had to bring Breezestar back. And right now he's going without a deputy because I don't know who else I can give the position to at the moment, because I definitely don't want someone to quit roleplay and let what had happened with Rock happened again.
Sometimes your options are just so limited, you'll have to go without a deputy for a while. It sucks in-roleplay wise, but it's the only thing to do out-of-character that's best for the roleplay as a whole.

So yeah. Hope that answered most of your questions.

Yes, actually, that answered my questions rather well. I still think that leaders should die a little more often, but I get your point.