Profile of mrgreenpath

Don't trade a minesweeper echelon, i would recommend replacing the echelon, but i think it works out better if you trade echelon because you end up with a repair crew (once you've traded with tank) which will be soon able to crit repair without risking it getting decrewed.

Obviously i don't know how skilled you are in micro BUT good macro in 2v2 can counteract a proportion of it.
answers
1) sounds like you have a hard time vs OKW. you have to learn to play vs their bullshit. for blobs my recommendation is katyusha. In order to get maximum damage/wipes get to the minimum range, obviously this is risky but the devastation it can cause is incredible. be especially wary of shrek blobs, make sure you have units infront of katyusha. you could also try baiting into demo charge. for USA 2 scotts are probs best for blobs, chip away nicely at them (neat trick if they dont have vet 1 smoke is to use normal smoke barrage nearby when they encounter trouble). AND if you see a t4 panzershwer, look to destroy it as soon as possible via (AT gun [use attack ground if cant scout it], short range katyusha, 120mm, tanks])
2)guards or shock. depends. you also want to be thinking what comes with these doctrines, you'll want to balance out with the usa player since they dont get any heavies. if you are getting fingered up the arse by light vehicles, best to just go with guards, shocks can also be very devastating but would only get one squad since expensive. but overall i would choose doctrine aiming for long term plan. I tend to choose doctrine based on the ostheer player as okw ones arent as threatening imo (pak 43 i suppose and no one uses jagdtiger anymore anyway).Main things to look to counter in ost doc are stuka bomber and tiger/elite. if they have stuka avoid b4, if they have tiger jacksons do nicely.
3) Don't really like phrase unbalanced, you just have to learn whatever the current metagame is and be prepared to counter it. OKW can be very strong, but blobs and forward hq are easy to punish as you know where they all are.
4) you said u started winning, then started losing. that is probably because you elo+ went up/ after 10 games you get ranked. then you get better opponents

losing ain't so bad when it is a good match, KV1 ftw!

just never go full retard mode

small thing to be concerned about but, why are g43/ppsh upgrade both at 3 cp? seems a bit late, since jagers light inf and shock troops come at 2 cp, why not all 2cp?