Re: Your laptop doesn't seem to be in the den
I think after articles, the word "would" might be the hardest word to explain.
What's that noise?
Oh, that would be John again, practicing his drum solo.
-- Here would is used in a way that is similary to "that's must be John" but to express annoyance, as 5jj says.
I would think (ha, there it is again, and I didn't even mean to use it on purpose there) that your friend meant it would be fun for HIM to work there with you, if you were already working there. Of course, his comma splice tells me he may not pay attention to the finer rules of grammar, so who knows.
If I worked there, it would be fun.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.