Why would you want to add 100-500ms of latency to every single DOM manipulation? Realtime means I click on something and something else happens, immediately, not a 1/2 second later.
All this to just save having to load jQuery in the client? Not sure I get the advantage.
You still have to load jQuery through the client. What it does is expose RPC.
So in your situation I'd believe what you'd see is the server sending the command to attach event handlers to the elements you're clicking before you start interacting with it.
Your concern is valid and you probably wouldn't want to program every DOM manipulation with nodequery, and that isnt required. Yes, you would theoretically want to limit the number of calls to the server the same as you would in any paradigm, and hopefully that would be the same as or fewer than an equivalent client-side application. Currently this is just an experiment and I dont recommend it for production.
All this to just save having to load jQuery in the client? Not sure I get the advantage.