Roughly 2 hours.
Less than 2 hours
It depends on what you mean by "major" (most departures, most passengers enplaned, most destinations, most international destinations). Generally speaking, though, the top three would probably be Dublin, followed by Belfast (City and International), and Shannon.
One can find information about parking at Belfast airport by visiting the official Belfast Airport website. One is also able to drive up and pay to park on the day at Belfast Airport.
30-50 mins approx, depending on the time of day you go.
Dublin Airport is located just outside of Dublin, Ireland. It is conveniently located near several major roadways and is a short 10 km drive from the city.
No. You could get a ferry from Dublin to Liverpool or Holyhead and drive from there. You could drive from Dublin to Larne, near Belfast, and then get a ferry to Stranraer in Scotland and drive from there, or you could just fly.
Blarney is in Cork, so to drive there from Dublin airport would take at least 3 hours on the motorway and could be more in heavy traffic.
It is a business campus located in Dublin adjacent to the N7, with access via a grade separated interchange two miles from the M50 orbital motorway and a thirty minute drive from the airport or city centre.
Bristol is nearer to Dublin. There are no standard ferries operating between the two. You would need to go to the town of Holyhead in Wales to get a direct ferry to Dublin, or go to Fishguard and get a ferry to Ireland and then drive to Dublin.
The Point Depot, sometimes referred to as the O², is only about 1 mile from the centre of Dublin city. There are various ways to get to it. You could walk to it. You can get a Luas tram to it. You could get a taxi to it. You could cycle to it. You could get a bus to it. You could drive to it.
Using the new moterways you can be down to the Clonmel in about 4.30 hours if the traffic in Dublin isn't too bad.
city centre to city centre would be approx 3 hours, depending on time of day/rush hour etc