They could, they don't need to give us any tickets for league games.
Yes they do. There's no set minimum allocation for league games but the only time a team would get zero would be on the advice of the police.
Do you seriously think Celtic might give us no tickets for Parkhead as a result of us only giving them half the south stand at Easter Road (which still represents almost 10% of the stadium's capacity by the way)?
It's a nonsense idea.
Oh and we can pick and choose when we give them the full stand. It's the home side's prerogative.