aerating: really good if you use chemical fertilizers, and if you intend to water improperly.
If you do everything right, the worms will be your aerators.
I usually apply less fertilizer just for that reason. So that might be why I have never seen any burn. As with anything, too much can burn. But since it is a slow release, it would have to be an awful lot!
Electric mowers: sometimes I'm tempted to try a cordless, but just haven't felt that temptation enough to actually part with money. Yet.