Improved Artillery - In all honestey, I doubt this will change. Its an ok tech, its got its usefulness, but I dont expect it to change dramaticly. Most important it “works”. Its simple and intuitive, exactly what larry likes in his techs. A one or two sentince upgrade
Rockets - Also, expect the same. Perhaps a range of 4 rather than 3, or a re-roll if you have multiple AA guns in range. That’d be fair I think.
Paratroopers - I like what ive heard about it. Importantly will allies be able to use friendly airbases to paratroop if one or the other doesnt have the tech. And will an airbase be within 3 spaces of creete for germany to attack…historicaly.
Improved Industry - The ability to repair at 1/2 price is neat, but the building of more units is almost useless. You cant get away with making all land units cheaper (if you make mech one less, no one would ever buy infantry) So perhaps it makes tanks, fighters, tactical bombers 1 IPC cheaper. And bombers 2 IPCs cheaper, but that might get out of hand.
War Bonds - In this scale game, 1-6 IPCs isnt really a big deal. Id like to see warbonds taken out, but if it has to stay…perhaps 2 dice. Or you can loan money to a friendly power
Mech infantry - Has been changed out, Heavy Armor in this spot? Or, maybe mech infantry stays and Infantry can pair with Mech infantry at 1:1 for a move of 2.
Super subs - its actualy pretty broken, not by its self, but with 6 subs and 5 fighters and 2 bombers on the attack its super broken. Maybe make destroyers only able to cancel subs ablities at 1:1
Jet Fighters - Another mystery here, with the Tactical bomber the possibilities for a 4/4/4 are not as open. Maybe hits from jet figters are assigned to enemy aircraft first if avalable. But THAT is monsterous
Improved Shipyards - a throwback to the old increased production, Its neat, I like it, it makes boats slightly more acessable to a power.
Radar - This is a crappy tech for half the powers, add “sonar” (Destroyers always fire with first strike at enemy subs) Or, and follow me here, powers with radar can scramble from any airbase, island or not, to any adjacent sea zone(s) involved in combat
Long range - This gets complicated, now i think if you get +2 move you can bomb japan from western US and land in aleutian islands (i dont have the board in front of me) the tech has to be only +1, or maybe the scramble from any base idea
Heavy Bombers - If they say its atomics, then make it a good atomic bomb rule, otherwise let h-bombers roll at 1 in interception