I was wondering if the present participle in French is actually used today.

It is.

It is very uncommon to see “Je suis jouant au foot” rather than “Je joue au foot”

Considering that the first is not correct, that’s not surprising.

Bien qu’étant malade soit agaçant…

Again something not correct. I fear you are trying to map directly English structure to French one, and that’s not working. We’d say “Bien qu’être malade soit agaçant”. But agaçant is not a present participle, it is a verbal adjective (it has to agree with the qualified noun, it can’t have complements). A present participle more or less replace a subordinate clause.

Il ne travaille pas, sachant qu’il doit entretenir son fils

Works more or less, I feel a tension between the meaning which wants the “subject” of sachant to be the listener and the sentence structure which wants it to be il (BTW your English version has the same issue to my non native speaker hears). Something like, “Étant paresseux, il ne travaille pas malgré son besoin de rembourser ses dettes” works.

Ce ne sont pas des traductions académiques, mais ce qui vient naturellement à l’esprit :

• on change la conjugaison du verbe en changeant de langue :

  Although being ill is annoying…
  Bien qu’être malade soit ennuyeux
  …

• et on inverse la construction de la phrase pour la fluidité de l’expression :

  He doesn’t work, knowing that he has to look after his son.
  Sachant qu’il doit s’occuper de fils, il ne travaille pas.