Yes, but once in the league they then have access to Premier League finances. Celtic are a massive club made irrelevant in Europe by the lack of access to the riches of the other clubs from the top leagues.
Depends how they are managed. Newcastle only did that because they were poorly run. They should be, and always should have been, one of England's top clubs.
Possibly, but a Celtic in the Premier League would mean they instantly take on Premier League finances and would have spending power too. They are a huge club. They played Hearts at home recently and had 58,000. If that ground expanded they would be getting more than United, easily.
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