Ear training problems

One thing that would help with numbers 1 and 3 is to join a choir. It is good for ear-training and developing your voice (and sight-reading), plus it is very social. This is a tip in the anything category

 

one way I was taught to go about melodic dictation. This is just one method, there are many, maybe this will work for you, maybe not. You're usually given the first note. Which is cool, now, instead of stressing over each and every note as they progress. Try getting the first and last notes of each bar first. Then, once you have those, fill in the blanks as you are allowed subsequent hearings. If you approach the dictation as a whole passage of greater than 4 bars, and don't waste all your time trying to perfect 1 note/bar at a time, you are more likely to spot the harmony on a whole and you will likely have an easier time filling in the inbetween notes. Basically, you're trying to create a framework that you can work with instead of just taking stabs at what you may or may not hear. So, usually, I chart out the rhythms first, then the first and last notes of bars, then I use any subsequent listens(most official ear training test I've done give 3 listens for melodic dictation) to fill in the blanks.

I've always felt a sense of openness from 9 chords that 7th chords typically don't have. There is a sense of it being suspended, which, makes sense since a 9 is similar to a sus2. I don't know if that'll help, but that has always been how I personally identify with 9th chords

As for your voice 'sucking'. That's inconsequential to your inner ear sucking. Ideally you can have the worst voice on the planet but still have a terrific ear. Yes, ear training classes often have you sing or try to teach you to sight-sing...etc. But ultimately, more importantly than those types of exercises is INNER HEARING. You don't want to ever have to rely on singing something before you can hear it. You should hear it before you sing it, you should not only hear it but be able to manipulate it in your head before any note leaves your body. That is a far more useful goal than just being able to sing.

That said, I've met some cats with absolutely horrible voices, they have a hard time keeping pitch, a terrible time with dynamics and all in all, a hard time with ear training classes. But they still can develop it and get to a point where they can sight sing and get As. So, it's not the end of the world if you have a ****ty voice, that can be improved. But remember what I say about inner hearing. Your ear is what you're training here, not your voice.

There is a program for the computer, I forget what it's called, but when hooked up to a mic, it will chart your pitch on a line graph as you sing. It's a very useful tool to help you sing in pitch. I've personally never had issues with that, but I'm fortunate to have a nice voice. Still though, I have a good voice, and good control over it, but I do encounter intonation problems. What helps me, is to sing long pitches and think about the subtleties in the pitch. Try and sing it as solid as you can, then try bending the note ever so slightly to feel what that's like. Then try moving it up different intervals....etc. Always trying to feel and listen to your pitch as intently as possible.

Like all things, it just takes practice really. Get a tuner if it helps, try and find that program if it interests you. Don't bite off more you can chew though. If you're struggling with arpeggios, then back off and just sing intervals, or just sing pitches, nice and long...etc.