A quick search in PHPStorm reveals 37 in-code usages of node_load(). There will be a few more occurrences of that in the menu system (@see 'access callback' => 'node_access') which have to be replaced with requirement checks in the new routing system. I'd suggest postponing that part of the conversion and only replacing the obvious invocations of that function and keep node_load() until it is also deprecated for %node loading in the menu system.
Considering the above and due to the suggestion of not replacing node_load() in the menu system just yet makes this a Novice task. Anynone interested? :)