I can't answer your specific questions but debated the whole shared/not shared bathroom question with myself before booking to stay 2 nights in December last year. Given the prices are so reasonable I decided to go with the private bathroom. Probably if you need to ask then it is worth the extra cost :)
I had a room on the second floor. The bed was comfortable (quite firm). This is a super place to stay, the people were lovely and the breakfasts are delicious.
PS I am 64.