Why turn all these off: FCMEN_OFF, IESO_OFF, WDT_OFF ?
Since you're using the internal OSC... there's no need to use the internal/external switchover feature, same goes for FailSafe clock.... check out the datasheet for the whole set of crispy and ... obscure... details

WDT_OFF? It's really up to you to decide, I tend to left it to ON... but, it's always case by case... still the datasheet will provide you some detail about the benefits of WDT to ON.

Are these two statements redundant:
OSCCON = %01110001 ' Internal 8MHz osc.
DEFINE OSC 8
No they're not, the OSCCON line specify the OSC speed to the PIC, while the DEFINE OSC specify the OSC Speed to the compiler.