Re: St. Ninians, church or place (Stirling)
From the point of view of family history, St Ninians is a //parish// in the county of Stirling. It happens to be next door to the parish of Stirling, and is now effectively a suburb of the city.
The really important points to understand are (a) that, until the 19th century at least, the parish was the basic unit, not only of the church but also of civil record-keeping and (b) that most events recorded in a parish register did not necessarily take place in the kirk building. Unless you find a record that says specifically that a wedding or baptism ceremony was performed in the kirk itself, or that the witnesses to a baptism were the congregation, you cannot safely assume that it was.
Most wedding ceremonies, for example, were held in the bride's parents home or, if she had no parents living or was married a long way from home, in the manse (the minister's residence) or in her employer's home. Baptisms too were often performed in the parents' home. Kirk ceremonies became common only during the 20th century, though I myself was baptised in my parents' living room, and I have been a bridesmaid at a wedding in the bride's parents' living room.
So you must not assume that James Lowrie and Grace Monteath were married in a kirk building. In 1829, in fact, the overwhelming likelihood is that they were not.
For background about the parish of St Ninians, see https://stataccscot.edina.ac.uk/static/statacc/dist/parish/Stirling/St%20Ninians
For more information about Scottish marriage customs see https://www.gla.ac.uk/schools/socialpolitical/research/economicsocialhistory/historymedicine/scottishwayofbirthanddeath/marriage/