Exactly this. The bike will get very disconcertingly close to the red before the fan kicks on, but when it does you can hear it, feel it, and your lights will dim momentarily.
You should be able to run a hot wire to one of the nodes and the fan should turn on.
650's tend to have to get almost to the red before the fan turns on.
As for a weep hole leak if the bike has sat for a while then run it and it might go away. Otherwise you need a new mechanical seal and we have an easy way to do that. Just watch your leak.