I can only hint at question one, but according to this arctile https://carto.com/blog/MVT-mapnik-vs-postgis/
"We may also consider removing the ST_Simplify and ST_SnapToGrid as
they aim to facilitate raster rendering and it’s done by the MVT
I would recommend using GeoServer for this.
It can generate tiles as geoJSON natively and can installed very easily,
setting the GEOWEBCACHE_CACHE_DIR environment variable will let you choose where your cache of XYZ tiles will be genrated.
You would need to add a data source from a folder of shapefiles, and then publish the layer from the file you want to ...