It doesn't necessarily mean all your channels will force close, only if a partner tries to close while you're offline or an htlc is stuck

Ima guess it’s energy so it would go into cold storage till pulled up again

It doesn’t force close a channel. Force closure happens when one of the two parties initiate it. The exposure would be if you drop offline and your channel counterparty force closes with an inaccurate balance and you being offline. This is why it’s good to set up a watchtower for protection

Node Offline

No, your channel can be offline indefinitely. The other party can force close while you’re down, though.