I am new to the whole trad hunting thing. Have had an old Bear bow a few months. I am building my first board bow from red oak, pyramid style. I am excited ,been a carpenter my whole career and have a gut feeling this is going to be fun and work out. Question is, if the bow turns to be a shooter, will it degrade the strength-life of the bow to decorate it with some wood burning designs on limbs and the like? Of course I will be using a hobby iron.

I for sure wouldn't do it on the back,the belly might be alright if you do in a non working area
or at least in a low stress area. Handle and fads should be OK.
  pAPPY

Yeah, I agree with Pappy.  There's a guy over on another site that carves wood spirits into the handles, they looks great.

I used to use a burner for the specs and such on the belly fades. Never had an issue doing that.

I've also used it on belly's,fads,tips on a few of my selfbows.Never on the backs.