The importance of running a node as you already know is trust, privacy and decentralization, with privacy and adding more security or decentralization to the bitcoin network against attacks like Sybil attack is the reason it is advisable to run your own node, but dealing with a centralized exchange where your details are already shared with defeats all forms of privacy so the whole idea of running for privacy is dead already. As for running the node yourself to help the decentralization of the network it is a great idea.
Running a node (bitcoin core) isn’t a lightweight program on laptops but with the device specs you stated above it will do just fine, it is not necessary to have the device turn on 24/7 although that is the best thing for the network but you can sync or verify when you power on the device.
Not making transactions regularly doesn’t mean you don’t need to be node runner you can be a node runner for not just you but for others close to you to connect to your node as it is also your part of keeping the network you hold its coin secure