Do I have to file return with no transactions

[Ned Carey]

In another thread Steven Hamilton II wrote

This brings up the question do I have to file? I have several companies.

Do I have to file in the following scenarios?

1) New company has not done anything yet and has no assets no bank account, no transactions.
2) Has assets but no transactions other than the purchase of a property.
3) Has assets, a property was purchased, the only expenditures were capital improvements, no expenses. but no income.
4 has assets and expenses but no income.

Presuming all are LLCs, some might be single member some might be multi-member.

thanks,

Ned