First, bag checking is only on the first flight of the day, if on a single ticket it will be checked thru to your destination that day.

The other issue is likely a display error but without some visible documentation (the original offer/purchase, the present ticket itinerary) doubt anyone here here can help. Suggest calling and asking a UA agent these questions.

Some bundles are OW, some roundtrip. But you should not have a difference for a flight in the same direction. Also be aware is a few smaller aircraft do not have E+. (is the extra charge for preferred seating and not E+?)