Well, "ku" is a bit shorter than "zo'e", and sometimes can be elided.
Neither is a very convincing reason, but I can't think of any other at
the moment.
> How do I say something equivalent to this,
> preferably with the same kind of extensibility, or can I not do so?:
I doubt that you cannot say something in Lojban that you can say in
English (or vice versa for that matter). The only issue might be how
longwinded you need to make it, but not whether you can say it or not.
> I went to my house. Define the time at which I did this to be A. Before A, I
> left the store. Define the time at which I did this to be B. Before A but
> after B I went to my friend's house.
mi klama lo zdani be mi ca .abu .i pu .abu mi cliva lo zarci ca by .i
ge pu .abu gi ku'i ba by mi klama lo zdani be lo pendo
> Thus unambigously establishing the sequence:
> I left the store. Then I went to my friend's house. Then I went to my house.
> without actually needing to come up with the events in the sequence in the
> order that they occurred. Granted, the idiomatic way to say this in English
> in this order would be:
> I went to my house. Before I went to my house, I left the store. Before I
> went to my house but after I left the store, I went to my friend's house.
> but we have {goi} to avoid this kind of thing already.
The idiomatic way to say it would be to tell the story in the right
order: X and then Y and then Z. If you somehow need to insert
something that you forgot to say, it will take some effort, in any
language.