When I filled the front of my three column sash long ago my mom continued sewing them right side up wrapping up from the bottom. I have also seen them start over again on the top of the back.
As to placement on the sash, the BSA Insignia Guide is now online:http://www.scouting.org/media/insigniaguide.aspx
Under Merit Badges, the Insignia Gudie is silent except to say that:"Cloth badges with silver border, Boy Scout, right sleeve, position 4 limited to six, merit badge sash no limit."
I can find no written restriction on where you can place merit badges on your sash. I would suggest that a Scout use the customary rows of three perpendicular to the sash sides. There are self designated "Uniform Police" at every district or council function and in the crowd at every parade. It is not worth the boy's embarassment.
I can think of no circumstance where it is appropriate to wear insignia upside-down. Protesters at our National Meetings sometimes wear insignia upside-down in protest. I would never want anyone to think I was protesting or trying to be disrespectful.
As to temporary patches, that is also carefully explained in the Insignia Guide:http://www.scouting.org/media/insigniag ... px?print=1Temporary Insignia"Temporary insignia are issued for such events as summer camp, camporees, and Scouting shows. All temporary insignia must contain identification including one of the following: corporate name (Boy Scouts of America); corporate initials (BSA), BSA fleur-de-lis (universal with eagle or plain one-color), "Venturing BSA", or "Venturing"."
"Order of the Arrow regional and national meetings and training activities may also provide them (the totin chip patch is also temporary insignia). Only one such patch may be worn at a time. The patch is worn centered on the right pocket and must not exceed the dimension of the seams of the pocket, nor extend higher than the lowest tip of the pocket flap. It may be either sewn or suspended from under the flap attached to the button. "
There is no provision to wear more than one temporary patch or to place this patch anywhere but over the right pocket...i.e. not on a sash.