As far as I remember I rarely added "ban" to village names since it seemed redundant to me.
BUT probably it would be better to add it, since in 98% of all villages it is basically part of the name. Locals always say "ban......" when speaking of a village.
There are only a few cases of bigger villages / small towns where the "ban" is dropped.

Actually I didn't use a TMS layer but Landsat 8 raw imagery which I processed in GRASS GIS (using basically the near-infrared band), convert it back to the OSM format (using an aged version of ogr2osm) and adapting it to the existing features (in JOSM). Long time ago I wrote a blog post about this workflow and although back then I used Landsat 7, it is basically the same for Landsat 8 without the need to remove the stripes: http://www.webrian.ch/2012/02/armchair-mapping-using-grass-gis.html
Meanwhile I mapped several other reservoirs and since development continues in a high pace, work continues as well.