Is it OK to nominate someone without their prior consent? If I nominate someone without asking privately first and the person does not accept, (s)he will have to turn down the nomination publicly. Some people may not like this kind of pressurising.

Not that I am too bothered personally. I would ask the person first but I did not mind turning down my nomination publicly the last time. I also promised to accept it this time and I am happy to keep the promise if needed.