With your first problem, there are a couple of things going on, and it's good to nip this one in the bud, as it can quickly spread to uncontrolled barking in other situations.
For one thing, a lot of the people at our doors are never given access to our homes (delivery people, canvassers, missionaries, whatever ...). Dogs take many of their cues from us; as far as the dog is concerned, many visitors are unwanted, turned away at the door, and barking winds up being a pretty common problem as a result. (The mailman is a classic.) And even better yet, the dogs think they're "good at this", and who doesn't like success? As they see it, they bark, "visitors" leave (doesn't matter that they were going to anyway), the home has successfully been defended.
Another thing that often exacerbates the issue is we tend to be more focused on answering the door than on dealing with our pups past a certain stage in their training. Can't leave the delivery person or neighbor waiting, after all... And we tend to get annoyed. Either way, your "energy" is a little off. (Personally, I don't think I've ever been able to teach a dog anything while I was annoyed or rushed.) It helps if you're calm and relaxed, maybe take a deep breath, you're crate training, so crate your dog and *wait* for him to settle (if not practical, send them to their spot and the same). And you want him to really settle. One of the biggest mistakes we make is making our own commands meaningless. If you give a command, there needs to be follow through. So if you say "quiet", there can be no growling or whimpering when you're finished, nothing but quiet. Nothing else happens until quiet happens, and tbh, I'm lukewarm on rewarding if it didn't happen in a timely fashion. (No treats, less praise.) There needs to be a difference for following a command or eventually getting around to it. (On the other hand, make sure to never punish a dog for doing what he was told to no matter how late. ("Come here" when a dog has run away is the one where that usually goes wrong for people.) Ignoring them can be punishment enough. You get a feel for it.) If for whatever reason you need a shortcut at some point (you know he isn't ready to be quiet and you don't have the time to see to it), then the command given then has to be "crate" / "spot" / your version thereof, so you aren't sabotaging yourself and your dog. Don't set them up to fail.
Be careful that there's no escalation or frustration, this isn't a fight. You gave a command and that's the bottom line here. You need to stay there by the crate - calmly - and wait for it to happen, not leaving his side until it does. Generally, the time it takes will shorten with every iteration as long as you stick to it. (Posting a note on the door for a couple of days to just leave packages there or that you're training the dog and it can take a moment to answer the door has a way of helping take the feeling of pressure off you. If you don't seem in a rush to be elsewhere, your dog is a lot more likely to respond to the lesson.)
Any time your pup seems to be falling back into those ways, you need to get on it, preferably quickly, and insist on the result you're after. Pretty much as a rule GSDs are wicked bright and eager to please. Communicate what you want, clearly, in ways they understand, and they're happy to deliver. Just remember that for them, a lot of the communication happens by observing our behavior, and they're bright enough to try to fill in those gaps. Unfortunately their solutions aren't always the best ones for us. ;)
As for problem two, two things: 1) is he neutered? Because that solves a lot of issues. Basically you have a teenage boy on your hands... And 2), follow through. See above. Redirecting is useful for a lot of things, but chances are in this case he's too excited and just won't learn; he's no longer receptive to the lesson. Pick a day off to practice. She begins to enter the home, he comes running, she turns and leaves. Repeat. Repeat. Repeat. Don't let him get to the point where he can jump, jumping is *not* going to be a thing in your household. Period. (A harness to grab him as he tries to race past can help you give her the time she needs to leave.) Eventually he gets it (sometimes it does help to give him a hint, words, physical assistance, but he'll need to grasp the connection on his own), if his butt isn't on the ground, if he isn't giving her space when she opens the door, he doesn't get access to her. Period. Greeting her is a reward. Insist on him staying there until she gets a chance to get inside, hang up her coat, keys, whatever and select a spot for greetings to take place in a more orderly fashion. (We sit on a bench in the entryway or the first step of the stairs.) If at any point his butt leaves the ground before either of you allow it, she leaves. Repeat repeat repeat. (Where we go wrong on that one is we generally like being greeted enthusiastically. The more energy you pour into the greeting, the wilder he'll get. Try to keep it calm-ish.) Jumping still isn't okay, not even then, if he starts, he gets banished to his crate, no greeting, or she leaves (whichever is more practical at that point). Repeat. Repeat. Repeat. It's okay to be petty when the results aren't quite right. In fact, it's often necessary. Over time you'll learn where you can give him leeway and where you can't, which lessons he's fundamentally grasped and accepted, and which ones he's sort of winging, just waiting for you guys to give him an opening to do it his way instead.
Harnesses... We have three. Two from Julius K9, the old model (from our last dog) and the newer IDC powerharness. The second is definitely a better fit, and reduces the amount of force our GSD can exert when pulling noticeably. I can definitely recommend it, although they have a bunch of others I haven't tried that could be better. They definitely put thought into design and have me sold on the results. Neither of the ones I have will keep your dog in the harness if he's an escape artist, but they are great for walking and for safety issues when seat-belting in the car. (In the event of a sharp stop, attaching your dog's collar to the seatbelt extension might keep *you* safe, but definitely *not* your dog. A harness, on the other hand, can. That was important to me. Our girl doesn't go anywhere in the car without the harness and belt, even when she's in the back.) As for the third harness, I need a cane to go longer distances, so I tend to use a halti harness to guarantee no pulling or lunging. (Note: it took a little practice for us both to get there.) Nominally it's a two hand affair, which puts a lot of people off, but if I can make it work when I'm effectively a hand down... (Hubs hates it, but then he also doesn't need it. It's a mileage varying kind of thing.) But I can hold her one handed with no issues, even when she's startled by the occasional cat, jack rabbit or fox, and that's kind of huge for me. It also has the advantage of clipping onto her collar, so no escaping. I think the Amazon link had videos of the halti in use (couldn't get them to load), so maybe give it a look or check youtube. (The gentle leader halti for noses wasn't an option for our current dog (although it worked amazingly well on the last one), because she was so stubborn about pulling and would fight it, in which case it can cause neck injuries.) Basically there isn't really one solution, it needs to fit your specific needs / situation.
My girls currently have a very similar looking harness with the front and back clip, They are both mostly well behaved non pullers (with exeception of an over stimulating situation!) but I'm looking to get something that has the front clip and preferably a handle but is the Y shape that goes over the shoulders instead of across them.
this is thier current harness ...