I have had no problems leaving it closed most of the time and only opening it up when I need to make a payment. But since I live on bitcoin and use it in several of my day to day purchases, I generally open it up multiple times per day. Electrum also has a watchtower option so you can find someone who's running one and ask them if you can plug their watchtower info into your electrum wallet.

Watchtowers do not have custody of your funds but they do have some presigned transactions they can broadcast to close your channels, and you're trusting them to do that if you don't think you can get online in time to punish your counterparty if they try to cheat. There are instructions for running a watchtower here, consider running one for your friends and having them run one for you. It is my understanding that if you don't use a watchtower, you are safe as long as you open up your lightning node at least once during every two week period.

If you only need your node as a wallet to pay sats from time to time, you can open private channels to some large peers. This way your node won't be routing other people's payments and it will be safe to shut it down whenever you like. But if you have public channels to receive sats or earn some routing fees it can be dangerous to turn it off. You must make sure there are no pending htlcs, or the channel will be force closed when one expires.