Usually you have your first truck out at minute 2-3, second at 8-9.
20 Fuel is about 1 minute of fuel income. The point of delaying it is to give soviets a breathing chance in early game. This changes will improve volks late game against vetted allies infantry, there's no need to overbuff them for early game. The Kar98 damage increase is enough for that.
The tankhunter squad could've two AT rifles together which are replaced by schrecks, the point hereby is that upgrades should be tactical decisions for every faction. Not no-brainer choices.
I personally don't upgrade schrecks anymore, simply because good players know how to deal with them. You get pushed, kited & bleed to death. Raketenwerfer + mines are more effective.
It's enough to lower the vet requirements. So that okw units actually reach vet 5 in reasonable time.
I totally agree with AchtAchter, in 90% of my OKW games I don´t upgrade to shrecks, but use a lot of mines and Raketenwerfer.
Since the shreck blob is the only problem why OKW doesn´t get any buffs, I´d be in favour of removing it from Volks and providing a snare ability and a small AI buff.
On the other hand Obers should get a cost and vet requirement reduction since they are far away from their Übermensch performance pre nerf and don´t scale well against other elite infantry or Rifles with 1919´s.
The Luchs is a cool unit in my opinion, but only from the design point of view. I never build one, since it comes much too late and the impact is pretty decent, but not enough. Though I don´t know how this could be changed. Moving it to another Tier would be too much. Perhaps tweaking its stats a bit?