It's too late now. Democrat thugs are keeping Trump off the campaign trail too much as is. Democrats are useing the law as a sledgehammer against their political opponents. That's horrible. And God only knows what totalitarian nightmare they'll come up with next. Trump needs his time to talk with 'the people'... and to get out the vote.
Never thought I'd see the day the law in the US would be used as a weapon like democrats are doing now. It's so third world.
Anyhow, what little time Trump will have to campaign can't be spent in the House babysitting Republicans. When Trump's President he'll be able to unite the party and add some structure to Congress. But again, like you - I love the idea of him being a temporary Speaker .... it would have been fun - and so productive.
If Trump ran for Speaker, even without the lawfare, it would not be any means easy. If he did run, I would expect them to floor the lawfare accelerator.