Hi there. You’ve got a number of questions in that post, which I’ll answer out of order.
- Do you need to wait until you’re not sore? No, as long as the soreness isn’t interfering with your ability to exercise (i.e. you aren’t walking around like an old man and wincing with every arm swing) you can lift again.
- Decline pushups - you mean, feet inclined? That’s a good way to make pushups harder, for sure. The higher you go the harder it is, up to the handstand pushup.
- Is the military press better? Eh, to me, a standing shoulder press is a standing shoulder press. Strict military presses with the feet together seem a little less stable. Do you mean seated vs. standing? My opinion is that you should definitely stand, it forces you to watch your form and tighten your abs...when you sit you can relax a bit and still get the weight up by leaning back into the seat back. I think it’s better to stand and force yourself to provide that support.
- Training legs more often - yes, for sure. Why not stick squats in one workout, deadlifts in another? That way you work the legs hard each time. Not sure where calf raises would fit better...I’d probably do them on squat days just because you’re already setting up for a similar exercise, assuming you’re doing barbell squats and not one-legged dumbbell squats.
- Your workout has a lot of overlap in it. For example, your Day One back/chest workout also works triceps hard (chest press, pushups, pullups). Then you do shoulders on day two with shoulder presses (also triceps as you extend the weight to lockout), day three you hit them specifically (you didn’t say with what exercise), and then day four has the triceps hit with dips, pushups, and pronated grip pullups. Chest gets a lot of work on days one, two, and four. Shoulders get work one one, two, and four. The lats will be working on all four days - three if your barbell shrug is straight up and down, if you’re leaning forward for an incline shrug your lats work too. That might be a feature or a bug for you, but I think it’s a lot of work. You can get by with less direct arm exercise and less exercises overall and still grow...very possibly grow more actually. I’d skip the raises, flys, curls, and extensions. At least for now.
It’s generally easier to split by function - push/pull/legs. Or split by upper/lower.
Generally the folks who hang out here favor full-body workouts with really stripped down routines - 3-4 exercises, maybe 5, per day, 2-3 times a week. Emphasis is on a few big exercises done for low to moderate reps rather than a bunch of exercises for the same body part. I do a once-a-week deadlift/bench press/shoulder press/bent dumbbell rows routine because of scheduling issues but fill out my week with crossfit works and MMA training. Other folks here do push/pull/legs splits and alternate sets between push and pull. Others do similar basic routines.
For ones like that, check the basic routines sticky at the top of this forum for the Rippetoe Starting Strength routine and the Mahler twice-a-week full body workout. You can also split upper/lower like I said, which will be easier than back/chest, shoulders, and arms - since your arms get a workout whenever you do chest (triceps especially on dips, chest press, pushups), back (biceps especially - any pullup works biceps), and shoulders (triceps on the shoulder press).
The other guys here will probably have lots of additional advice for you.
Hope that helps. Good luck with your lifting.