I think the one on the right is for pipe, used after cutting to length to de-bur.
The screwdriver in the center is a screwdriver. Use it for whatever.
Yep. Both reamers may have been for pipe, but certainly the one on the right is.
If you get threaded pipe (galvanized water or black for gas) cut at the hardware store, the machine will have an almost identical reamer - the business end, not the square taper - in a holder that pivots off the back of the machine to ream off the ridge left by cutting.
Time was, nearly every trade had uses for a brace. For instance, I've got a bit used for automotive valve grinding, with two little adjustable tangs to fit into the divots on early automobile engine valves. There's been something of a rediscovery of the usefulness of braces for purposes other than drilling holes. Lee Valley offers both a 3/8" square drive bit, for use with sockets, and a 1/4" hex bit, for use with insert bits for screwdriving.