Everything was very clean and both helped me in everything they could (I was a totally newbie in Sanfran). They have a very funny dog, if you like dogs, you will love him :)
The house is very close to a very high hill. You must take a look to the views of the city from there!
The bus 24 arrives pretty fast to The Castro. Also you have not too far away the line J (muni train - 5 min walking) and you will be in Embarcadero in about 30 minutes, and I recommend you to make a stop in Mission park Dolores, there are some amazing views of the city!. You will also have the possibility to combine the bus 24 with the line L/M, but combining at late hours means that you will need probably to wait a bit until the next train/bus.
Also there is a safeway not too far away (11min walking).
And finally the area feels pretty secure even do at night.