How to spend the in-game resources

So, should I upgrade tech or wonders first?
What is the priority within battle resources?
How to go about tech requiring energy?
Is there a minimum tech or general requirement for the 1939 challenge conquest

Only real use for upgrading nukes further than Manstein states is to stockpile them, as moving to Hydrogen increases your stockpile from 9 to 18, but they’re expensive and take longer, too.

Practically speaking there’s few situations in which you’d need hydrogen, let alone antimatter, bombs. And hydrogen and antimatter bombs cause splash damage, which can make them undesirable at times as the splash damage isn’t enough to kill surrounding units (or even practically injure aliens) but is enough to nuke your own units to not being useful on an offensive.

For farming, space mission wonders are awful. You can get them if you’ve upgraded all wonders and tech already for the sake of completion, but you won’t notice them, even if you own Manstein’s perpetual bonuses. Way too slow, hard to justify how slow.