Hi Colin. Yes and yes (churchyards) - see Manx Notebook - link at the top of the screen, which tells you all about the churches and churchyards.
William could have been born in Laxey, Lonan, as he said, and taken back to be baptised at the church where his parents married, where their older children were also baptised, and where they would have known the vicar. Alice Jane Kerruish was living in Maughold before they married, and her husband John Kelly was born there, so it was their family church.
At the time they married John was already farming in Lonan at Skinscoe, and must have been accustomed to going back and forth to Maughold. Lonan and Maughold are adjoining parishes - see map: www.iomguide.com/parishmap.php
Also have a look at the ones in Manx Notebook. There is a "Search" facility where you can put in those place names associated with your family, including the specific farms.
Sue