There are currently no routine customs or Immigration checks between ROI and UK, but there are occasional security checks (escaped prisoners, contraband etc) especially on the ferries. This will change in the future as the UK and ROI are agreeing on border security.
No. There is a common travel agreement between Ireland and Britain. You will not need a passport at any time when travelling across the sea between Britain and Ireland. Neither do you need one when travelling in Ireland, from the south of the country to the North. There is no border on the island. There is open travel between the islands/countries of Ireland and Britain. Google 'Common Travel Area Britain Ireland' .
No, a South African citizen does not need a visa to visit Dublin or anywhere else in Ireland. If you are travelling via the UK (even in transit) I think that you now need a visa. (Not for Ireland but for the UK.) Worth checking out prior to travel just to be sure!
You would be travelling south.
Depends where you are travelling from
It is in the south midlands of Ireland.
It is in the south of Ireland, more precisely the southwest of Ireland.
It is actually in the midlands of Ireland, close to the centre of the country, so it is not in the north, south, east or west of Ireland. It is in the Republic of Ireland, which is sometimes incorrectly referred to as "Southern Ireland" or the "South of Ireland".
Geographically it's in the midlands of Ireland, in the county of Westmeath. When you refer to south of Ireland, you are asking if it is in Northern Ireland or the Republic of Ireland. Mullingar is in the Republic of Ireland.
No. Ireland is north of the equator.
No. Ireland is in Europe.
Swords is in the east of Ireland, close to the city of Dublin. Dublin is in the Republic of Ireland which some people incorrectly refer to as the south of Ireland.
Ireland is not a member. South Africa is a member.