I just remember my first play through... I tried to get one of each mana type... and raise that armageddon counter... managed both on a large islands map... but had my strongest troops being mages while horsemen of the apocalypse were flying around killing everyone... interesting but really odd game. (you gain lots of unhappy faces and unhealth as the AC rises, as long as the horsemen stay alive, as well as nasty events, hell terrain and general horror and death...)
Also, for mana, you benefit from having more than one of each mana type- free upgrades to mages (2 mana gives I, 3 gives II and 4 gives III at archmage, so death 4 would give 'death I' at adept creation, death II at mage upgrade III at archmage, the ability to become a lich and also +4 unholy damage for any death 'affinity' units (like wraiths getting stronger with death mana, druids with nature etc. While 4 mana nodes spread between fire, water, earth and air would give nothing free except allow you to build a wonder increasing summon strength.
...still fun to see what they all do though at some point. Best way is to demand vassals give you their mana on capitulation, that way you can quickly gain lots of mana types at the point you would have won (vassals can't refuse the first demand, future demands can cause wars). Also, I like some of the modmods at the moment... not all of them are as 'clean' with some missing text or broken bits... but new races are fun once you've tried those that take your interest.
