Cork lodging

Is it just you or are you traveling with someone? I didn't have much luck with VRBO/AirBnB in Cork. My friend and I booked an apartment through Booking.com, but sadly, I can't recommend it. Its location, on the other hand, we enjoyed very much. We were across the street (it was more of an alley, IMO) from the Residence Inn on the north side of the river. Around the corner was Sin é, an excellent pub with traditional music sessions. Also, an easy walk to the train station, and the bus to Blarney stopped by the pub. There are several hotels in that immediate area, both large modern chains and small independents. I have seen several posts on this topic here on the Forum, so do a search.
The second question is a head-scratcher. You want to rent a car in Dublin and take it to Edinburgh? I mean, you can, but you'll pay for the ferry and, I'm guessing, an absolutely massive drop-off fee. You could easily fly between these cities for less than $100.

Ok, lets forget about the car.