Corwyn has no Irish translation so it's spelt the same as it is in English.
It would be the same; no Gaelic equivalent'
Mary Corwyn's birth name is Mary Breninski.
There is no special Gaelic form of the name; it would be the same.
Oisín
The Scottish Gaelic form of the surname is MacIllFhionndaig.As a first name it would be Liondsaidh.(Some Irish families that adopted the name 'Lindsay' were MacClintock, Lynchy, and O'Lynn.)
This sort of name is left in the original form even if the last name is in an Irish Gaelic or Scottish Gaelic form.
Ó Cléirchín
The Scottish place name is Sruighlea.
As a last name Camshron.
You don't. Cheyenne is a non-Gaelic, proper name and, as such, has no Gaelic spelling.
A rose (flower) is rós in Irish;the name Rose is Róisín (a diminutive) in Irish.Scottish Gaelic: ?
The closest Gaelic name is Aidan, spelled Aodhán in Irish Gaelicand Aodhan in Scottish Gaelic.