Hi Dutchy02. I can't see your playercard, but gauging from your post, the first advice I would offer is just play more of all sides to develop and insight into their respective strengths and weakness and just get a general handle on play.
More specifically here's how I read the matchups
at this time.
I have been having trouble with fighting the USF and Soviets as OKW.
First everything I say below I say pertinent to my experience in 1v1 automatch (and 2v2 AT automatch). It is also applicable in 2&3v etc, but other buffering factors come into play in multi-partnered matches.
OKW are a hard ask right now especially. Most saliently in 1v1 auto. My take? Just don't play them vs USF. In fact, until USF are nerfed, don't play Ostheer either.
Just play USF instead and dominate.
Another poster was right about map vetoes. Minsk is akin to volunteering to lose for OKW in the particular.
USF rifle spam abetted by insta vet and 'nades is just BS. Unless you have reflexes of an 18 year old, are located in the US just a single hop away from Relic's battle server with a $4k PC so you can Übermicrododge their endless 'naderain, don't bother.
Just play USF instead.
vs Soviets OKW are viable. Kind of. But the forces are still IMBA so player skillZ matched for player, balance still favours Soviets.
In 1v1 all OKW can do vs USF is counter-blob, which becomes increasingly ineffective once past opening and early game. By mid game you'd better have a new repertoire of tricks to play or you're done.
I would also like advice on how to counter maxim spam supported by a vast conscript army.
From this sentence I'll wager you're trying to tech too fast vs putting men on the ground in the field. OKW's Achilles' Heel to tech in 1v1 will be fuel, so don't. Use the MP rather than floating it to put lots of VGrs into the field. If he's spamming maxims, he'll have to have built T2 for them. That costs time, fuel, and MP, and while he is building for that, his engies aren't in the field. He can't build conscripts and Maxims both. He won't have the MP.
OKW can spam VGr just as hard as Sov can conscripts, even harder if he is building T2 to spam Maxims. Clearly you need to be more aggressive. VGr can outgun conscripts squad for squad, and rape them with numerical superiority. Why aren't you doing this?
Offensive patrolling.
Rather than capping, like PE with its shitty opening resource model in COH1 (½ US inf squad cap/decap rate), as OKW your primary objective is to deny your opponent resource and movement with by a strategy of denial of resource and position. Cut his maxims off en-route. Catch his conscripts 2:1 and gun them down using OKWs strong opening infantry advantage straight out of the gate, 5 man, with good punch at range and decent resilience. You will have Inf superiority until he can field Shocks, and Shocks are expensive both to initially field or reinforce. If you let Maxims set up and then walk into their narrow arc of fire to have to beat a retreat or die, well what needs be said. You need to play cleverer tactically next time. Watch what you are doing wrong and figure out how you can change what didn't work into what will work. Don't blob if he has mortars and MGs is a just common sense. Either flank or over-run. Try to capture and recrew his Maxims.
Never underestimate the MP and positional & capping advantage of causing the enemy to bleed opening game by inflicting expensive casualties or wiping out entire squad models while you don't. And there's a secondary psychological impact, especially upon newer and less experienced players.
Forget Kubels IMV. They can be useful in certain specific situations, but generally, they are a waste of MP unless the map favors a couple of restrictive choke points where you can prevent his egress from his base and so contain his forces to routing via one side of the map or keeping him from capturing a particular critical sector. e.g. fuel or cut-off, and so cut him off. Kubels need to be stationary for 3 secs before their MG will suppress and are so fragile they are easily lost repositioning unless you are a master of micro. As someone else has already said, they have a very narrow window of operational viability.
The first and most general principle of victory is superior numbers. In opening vs Sov, OKW can field this if he goes T2 for Maxims, and equalise it if he spams conscripts. Go VGr not SP, as the later are too expensive, only superior at close range, and even worse, fragile being only 4 man. I love it when some OKW idiot thinks he is going to rape me with his SPs only to cut them down with triagulated conscript squads firing from range from behind green cover as the cross open ground to assault up close. Even if supported by a squad of VGr either behind GC or trying to assault as well, that then leaves them still outgunned and subsequently forced to retreat. So the msg is you are better off IME&V with more of and cheaper VGr doing the same thing as conscripts than SPs. Go a 2nd SP later once you establish intial supremacy rather than trying the hammer approach with them early if you want to. But remember SP will be completely outclassed at close range the moment Shock Troops hit the field, and a waste even in opening if you can't close ground to kill early because you are suppressed by MGs. Better you have several VGr so you can simultaneously assault MG from several sides. If he already has cross covering MGs, you have merely been outplayed.
Sov shouldn't be getting such a force build up and can't in opening without you constantly taking heavy casualties and squad losses for MP bleed along with retreating frequently also offering him free territorial control. It sounds like you need to think outside the bigger blob and just get more time on the board generally to get a feel for what works or doesn't. It's unrealistic to expect to be winning before then. Compounding that, OKW is definitely a faction that requires finesse whilst it has little to finesse with IMO. I CBF with them as they are, and against USF, suffice to say I'd rather just chew off my own arm and club myself to death with it then endure that.