Your flute and oboe duet sounds great. I've used woodwind duos before too, but usually of these types:
Flute + Bassoon -> Sometimes if I'm trying to evoke a pastoral scene in a chamber ensemble, I will use the combination of the mellow tone of the flute and the warmth of the bassoon
Flute + Clarinet -> These 2 are most similar in dynamic terms, although a clarinet can get up to forte in the low register, which the flute can't(I've heard from several sources that the loudest possible dynamic for the low register which goes up to A4, is mezzo-forte and that if there is forte written down there, it's understood to be a relative dynamic and not an absolute dynamic), but both can acheive an extremely mellow triple p dynamic down there
Oboe + Bassoon -> Sometimes if there is a piece that involves all 4 woodwind families, I will have 1 movement for double reeds exclusively
I've never really combined flute with oboe in a duo because I would always be in a state of:
Because I know that the dynamic tendencies of the 2 instruments in the low register are exact opposites, flute tends to be quiet to the point that too aggressive string playing, not to mention oboe presence can overpower the mellow flute(in fact, I often see orchestral density go down to 0 woodwind accompaniment(or maybe a quiet clarinet or bassoon at most) and pianissimo strings when the flute goes into the low register in an orchestral piece) whereas the oboe is super loud in that same register, too loud to play a piano dynamic down there(not much of a problem with the English Horn, a lower pitched cousin of the oboe, at least until maybe the lowest few pitches(similar to Bassoon in that respect)).