1. Depends on what you want to spend. The Fitzwilliam is the closest, but is expensive. The Westin is about a 10 minute walk. The Temple Bar Hotel is about 10 as well - and that's where I have stayed multiple times. They just recently refurbished the entire place, so the prices went up - but it is nice.

2. Tons of places around here - you're just barely south of the main strip in Temple Bar. You will find alot on Grafton street including American fast food, if that's your thing. O'Neills is a good place, again about a 10 minute walk. You will have no shortage of choices in this area.

3. Avoid politics and religion, just like anywhere else. You'll run into drunks later in the night on most streets and alleys, but I've never been bothered. At most they will ask you for some change, a quick NO is sufficient.

Dawson's pub is a cool place, a very small pub nearby. I would recommend you buy yourself a LEAP card, directly in front of RCSI is the Luas green line. You can take a ride out to the southern area of Dublin, lots of nice stuff to check out. Also nearby is Dublin Pearse which is a major train station - another good way to explore.

Any additional details you can post on what you want to spend or things you think you may like/dislike will help us give more specific answers.