Those ideas are beyond being considerable for two reasons:
1.: The side tech would be entirely pointless, because every OKW player had to go for it anyway. No grenades on their main infantry? No easy access to an alternative? That's the reason why USF got their ridiculous mortar and why everyone wants to keep it in the game, despite it working against anything the faction was designed for, which in term makes it completely unbalanceable...
Fair point. What I meant with having the nades be sidetech was for them to be quick and cheap allowing for a player to stick with t0 units a bit longer to deal with garrisons before choosing which truck to tech to. Ten fuel for incendiary nades into T2 luchs can be preferable to being pigeonholed into medic truck to deal with, say, garrisoned maxims.
2.: The costs you want to redistribute to other things would be extremely pointless, because these things are already fucking expensive. Sure, that would make healing and repairing (which is kind of stupid on OKW anyway, if we compare repair speeds with, say Soviets or Ostheer) more accessible, but at the same time nobody would ever again go for the retreat point, because it is on the verge of being unobtainable in anything but 4v4 already. At the same time, the cheaper USF tech gets their retreat point for free by the way, combined with cheaper healing. Something doesn't add up here.
I think you misunderstand, (edit, also, my wording sucked so I apologize for that). I mean to REDUCE teching costs, not redistribute the side techs. Medics would still cost the same, but Forward retreat point would be 100 manpower cheaper, and the medic truck would cost a bit less to set up. Similar for repair squads and as well as the previously mentioned side tech for incendiary nades.
If you want to lock things behind side techs, the teching itself has to become cheaper - that's the reasoning behind Brit teching being so bloody cheap. Alas, that adjustment never properly took place when it came to OKW and their healing (yes, there was an adjustment, but we can easily see now that it wasn't even close to being enough).
This is exactly what I am suggesting.