On the cave.10v24.net server, there's a place to give feedback. I will probably reply to your feedback personally, but if it seems of use to other people, I will post our exchange here, with your permission, using your login name (or not, if you prefer not).
Q: Am I supposed to be able to sell items? When I sell them they become the possession of the shop but I never get any gold for them.
--melde
A: Dear melde:
Historically, Angband allowed real buying and selling. This is still available as a "birth option" (only can be changed right when you start a character). The new default (the case in vanilla 4.1.0) is to provide more gold on the dungeon floor and not allow characters to sell items in the shop. Instead, they give items, and in return, shopkeepers identify the items for them. This was done to improve gameplay.
As far as testing -tr goes, I found it a little more feasible to get characters off the ground if I sold items for money, and it's what I'm used to from the old days. I'm interested in seeing what difference it makes for people. So choose whichever one you want, but, not until your next character.
UPDATE: The option to disallow selling (birth_no_selling) is now set to false by default (selling is allowed by default) but you can still turn it on (disable selling) if you want.