If you want to buy that headboard your style would be more modern french country or modern farmhouse. For rustic traditional I would prefer shiplap, iron, or no headboard.
I like the rug, but I see your carpet is beige I guess white would be nicer... you can look at the traditional rugs in neutral colors like pictures below, and buy a shipskin throw blanket instead!
Yes you can add wreath to your arch frames just like those inspiration photo. If you really love it do it. :)
I see your bed skirt is black, change it to ruffled white!
If you could find three arches you can make the headboard out of it. or buy 2 more to add on each side.
Q