AFAIK in league you can’t add any units to China or to France with a bid, and you can only add units to territories or Sea Zones that already have units.
The Chinese bid is perfectly legal in the Global `40 league (unless it just changed). Strictly speaking it is also legal to bid Chinese units which they cannot buy in the normal course of a game, but that probably will be changed if it hasn’t already. There has been plenty of discussion on that topic.
Placing a French bid in Paris should also be perfectly legal. I don’t think doing so would be that helpful since at best maybe you’ve delayed the German attack on S. France or Normandy by one turn, which i don’t see as having a lot of strategic impact on German play.