Religion: As long as you slot in somewhere ón the Pagano-Christian spectrum, beidh tu alright. Even atheists can handle Shaman Jesus.
Name: You must realise that the Gael has evolved for 1,500 to perceive Saxon/Viking/Norman names as a threat. To minimise this, gaelicise your name. You are still honouring your ancestors, but you are also signalling your desire to blend into Gaelic culture.
Language. The same. I learned Gaelic as an adult in six months. If you are smarter than mé, you can do it in less. If you are more stupid, it might take a year. Even mentally retarded native Gaelic speakers are able to learn enough English to get by.
The 26 County statelet hates the Irish language and if you try to use it with civil servants or politicians (even SF politicians like the fat and evil Martin Kenny in Sligo/Leitrim) or judges they will sneer, insult, patronise and threaten you with imprisonment or death. No exaggeration.
The Irish language is the nationalists' greatest shield against Deep State attack and the sharpest sword in our armoury.
I'll post in Gaeilge amháin here in future, le cúnamh De. Non-Gaelic speakers can use free translation tools to understand and to translate their responses into the dear, sweet old Gaelic. It will add just a few seconds to your response time and shows a respectful attitude. And it means the shoneen west Brit snitches in the garda surveilance unit will have to pay a Gael to translate!