Good advice ! Even that you do not use it so often, is better to sync it at least every week and better just do a simple payment, even that is tto yourself. That will keep updated the channels status and peers (maybe) will not close your channels.

By keeping long time a LN node offline, the peers will consider them as zombies and will force close your channels. That could end up with funds in limbo and indeed, you have to use the sweep option with chantools.

Very good guide.