I've finished installing my new mini 40A denso alternator and it seems to be sticking out a better voltage than the old one, steady 14.3 vs more like 13.5-14V on the old one. I haven't taken the car out for a proper test yet but but there are no squeals, chirps or sight of any misalignment so hopefully this will help with my battery issues.
https://www.flickr.com/photos/580680...n/photostream/
When I removed the old alternator it was a bit grumbly and free spinning so I think the bearings were on their last legs anyway. The idler pulley I had in there still feels nice and tight so I don't think that was a problem.
If the belt had been slipping a lot that could also explain my hot engine as the pump may not have been turning enough