I think the OOB tech rules need some major re-work to keep the game balanced, and one of the big reasons is the huge impact of LRA, HBs, and paratroops - all of which greatly increase the utility of bombers.
As much as I like playing games with tech, I think that I have to agree with you. Bombers already start out as as nice unit, but giving them 3 tech upgrades is a bit much.
Here are my thoughts on the 3 bomber tech upgrades.
1) Long Range Aircraft - This has always been a VERY powerful tech (assuming tech takes effect immediately). With this tech, a bomber can basically circumnavigate the earth in 2 moves or can strike almost anywhere. While fun, this is neither realistic nor fair.
The oceans should be larger which would solve this problem, but I understand the game balance idea to get the US into the game more quickly.
Perhaps LRA should only effect fighters or should only give +1 to the movement of air units.
2) Heavy Bombers - Gotta love 'em if ya got 'em, gotta hate 'em if your opponent’s got 'em. SBR aside, even with the reduced naval costs, Heavy Bombers just absolutely totally dominate naval warfare. This should not be so.
Perhaps this tech should only increase your bombers’ attack to 5 and your bombers’ SBRs to 1 die roll+2, or just totally lose this tech, and create a new, better, less game-breaking tech.
3) Paratroopers - Long missing from Axis & Allies, this tech totally changes the game into a different boardgame. I’ve already had several games turn into a Long Range, Paratrooping, Heavy Bomber fest. This is NOT how WWII was, and neither what Axis & Allies is or should be.
Perhaps there should be a completely separate air transport unit or only allow paratrooping on a 1-for-1 basis when attacking with land troops/amphibious assaults.