Buying / Listing Agent - Different or the Same?

Positives - person is aware of timing on both ends; potentially can negotiate a better price on exclusive/sell side; single point of contact; it is a common occurrence

Negatives - like working with a spouse - if you have a fight, it carries you through the whole day/process; you might get additional pressure to close on either end (you shouldn't if the broker is ethical)

I think this is a normal concern. I would still ask the broker to present a plan to market your apartment even if you have a positive feeling about the relationship. It seems like you are comfortable enough with this person, what is your reservation?

It is pretty common but since agent iis going to get paid on both transactions, I would try to negotiate a lower rate. That's typically what I offer to my clients when I represent them on both the sales and purchase.