The room on the ground floor has an own bathroom and everything else you need was provided by Alex and Angela. We only met Alex, a nice guy we had a quick chat with and who gave us a lot of recommendations on restaurants and pubs in the area. The place is a little bit off the real city center (temple bar is maybe a 20min walk), which was quite good to my opinion, since places typically get nicer if you leave the tourist area a little bit.
There is no key to lock the room. I think the hosts are absolutely trustworthy, but I can understand sometimes its just a better feeling to lock the room you keep your personal stuff in. Overall we enjoyed the 2 nights very much! Thanks a lot!