When should I use ,for instance, visit(as a noun) and when visiting(as a noun)?Is there a difference between them?
e.g. (In a letter) With regard to your visiting/visit ?
I'd go with "visit". It just sounds natural.
The visit is the actual time you're there. We had a nice visit.
The "visiting" is the process of going/staying there. With three children under the age of five, visiting anyone these days is always a process,
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
Only 'visiting' can take a direct object:.....With regard to you(r) visiting my parents, ...
This could also be expressed as: .....With regard to your vist to my parents, ...
Context is always important; labelling is rarely important.
"The Visiting" would be a better title for a horror movie.