In Irish it's "Tá mé níos fearr ná tusa"
Kerry have had more success in Gaelic Football than Mayo and have won most of their encounters, so Kerry would be regarded as being better than Mayo in Gaelic Football.
níos fearr ná ceann ar bith eile
Such a statement is open to debate. Different people will have different reasons as to why they prefer Gaelic Football or Soccer, so the question cannot really be answered definitively.
it is better to die on your feet than live forever on your knees.
It could be better translated if used in a sentence.
Nas fheàrr
In Irish it's "níos fearr"
This could be better answered if it were used in a sentence.
Yes. It is closer to Scottish Gaelic than Irish. It has a rather non-Gaelic orthography compared to the other two however.
Scotland speaks English and Gaelic. However, English is much more prominent than Gaelic.
It would be Cara as in English.
Context is needed to translate properly. A sentence is better.