Don't spend 3T is you have 0.5T and everything will be fine. You do not do it in a store.
A C3 nation you conquered will never have a negative cash if you move some money into it.
A game month of cash under -1T does not do much. A real month does.
Very few people have problems. we are looking into game statistics.
The ones who have, also have the cash but prefer not to move it to correct the shortages.
Construction can be bought from the portal market. It can be bought from the world market without any limit if you have the cash.
No limit as long as your stock is negative.
You can fix it with a single transaction.
Most players have nothing to do with this and nothing to worry about.
the problem is small and will be resolved as players do not wish to have their countries bankrupted.
They have clear messages about it, they had one week before and two more weeks coming to fix it.