[Omnirizon]

I wouldn't characterize Difficult Research as generally not a good idea. I would say it depends on the dynamics you are looking for, but just as often as not it, it is a good idea.

Granted, it favors rushers and big-blessers, but CBM takes steps to reduce the advantage afforded such nations (removing the Oracle from Mictlan, for example) and some games will forbid dual-blessing, or big-blessing altogether (although that latter seems extreme)

Were it not for the favor it gives some nations, I would say Very Difficult Research should always be used for MP games. It keeps things in each game stage for longer, and makes research strategy a much more powerful aspect of overall strategy.

Rare Events, however, is always a bad idea. It makes the Luck Scale way to weak, so that it is never worth taking luck, and almost always worth taking misfortune.