Just to be clear, are you saying you would be happy if Sky bought Super League and could decide which teams were in it?
Because that was the situation with Melbourne. News Limited created Super League and created the Storm to play in it. Following the merger with the ARL, News Limited continued to co-own the competition and so retained a vested interest in its success and expansion, losses at the Storm would be offset by profits in other parts of their business. Following the ARLC taking over the running of the NRL it no longer made any sense for them to finance the Storm, hence them selling the club.
If BSkyB were to finance a club they not gain the same benefit without share of league profits. While success could lead to increased subscriber numbers, those would be offset by increased rights costs as well as the risk of losing the sport to a rival broadcaster.
Also in 1999 BSkyB tired to takeover Manchester United but it was blocked by the government for being anticompetitive, this lead to NTL abandoning their plans to takeover Newcastle United. While rugby league is considerably smaller than the Premier League, the same arguments could be made, that a broadcaster owning a sports club would distort the market for sports rights. If so an attempt by BSkyB to own the Broncos or Crusaders could be similarly blocked anyway.
Could be but probably wouldn't be. RL doesn't have the same profile so fewer people care about its "issues".
I think the real issue is that Sky aren't interested in Broncos or Crusaders. There was a reason why they bidded for Manchester United and not Accrington Stanley. Wigan would probably interest them but Broncos / Crusaders is unlikely to.