If you're looking for a node with certain guarantees about the conditions in which they close channels, I'm not sure there's a universal way for node operators to share that info. 

Lightning network explorers might give you some insight into how certain nodes deal with channels - how frequently the close channels, the avg. life of their channels, etc.

Other options include using wallets that don't require channels: Muun, or going more custodial with a wallet that supports [hosted channels](https://fanismichalakis.fr/posts/what-are-hosted-channels/) like Simple Bitcoin Wallet.

k00b

I'm not really concerned about fraudulent forced closes, I'm more searching for a node who says "it's ok if you don't open your wallet for a month, but for compensation we require a little more fees than others" or something like that.

bitcoin

How to find out unannounced channel closing-policy?

Someone correct me if I'm wrong ...

Because your node is offline, for them to close the channel they'd perform a forced close which doesn't require your participation. The details of this close are published on-chain. 

If you are concerned about fraudulent forced closes (they publish a channel state that gives them more of the channel balance than they deserve), you'll want to setup a watchtower.

About channel closures: https://wiki.ion.radar.tech/tech/channels/channel-closing
About watchtowers: https://wiki.ion.radar.tech/tech/research/watchtowers

 