Everything you've listed is valuable. But some of those exercises will not produce as much improvement as you want. With limited time, I would scrap 2-5. Once you learn the Type A and Type B voicings (below), it's easy to drop out the 9th, 13th, etc. if you want a simplified sound. Tritone subs and diminished passing chords are nice to practice, but I would put them very low on the priority list, for a couple of reasons. First, once you learn all of the major and minor II-V-I voicings, you'll already know how to play the tritone subs. (If you're playing rootless voicings, adding a tritone sub is equivalent to playing over an altered dominant V.) Also, the passing diminished chord isn't common enough in modern jazz to warrant the amount of time you would dedicate to it. It's easy enough to learn in the context of a song that might require it.
Here's how I would spend the limited practice time:
1. Practice major ii-V-I's in all 12 keys with licks
Practice drill 1 from your list above. One nice way to do this exercise is to play the 3rd and 7th in the right hand and the bass note in the left hand. Hearing the bass note along with the 3rd and 7th is a useful ear training exercise. It avoids some redundancy that might occur if you were to practice the 3rd and 7th alone in the left hand, because the left hand will learn where the 3rd and 7th are anyway with later drills. For example, once you've mastered playing the 3rd and 7th, I recommend moving on to rootless Type A1 & Type B2 voicings in the left hand. When playing a II-V-I, you'll have to switch between the two types (e.g., A-B-A or B-A-B) to maintain good voice leading. While practicing the Type A and Type B voicings in the left hand, I recommend simultaneously practicing a II-V-I lick in the right hand. This will be more productive than the activity you've suggested, of practicing straight arpeggios or straight scales--I see these as low-yield activities that don't really expand one's vocabulary. When improvising, an arpeggio only sounds good when it's nestled around other devices, like a scale run, or a scale pattern, etc. If you're going to dedicate a significant amount of time on something, I say it's best to make it immediately applicable: write a lick that incorporates part of an arpeggio, scale run, etc., and practice that lick in all 12 keys in your right hand while working on the II-V-I A-B voicings in the left hand. Once you have your lick, work out a comping rhythm for your left hand chords that complements the lick. If you're transcribing, you can draw from those transcriptions for inspirations on your lick. (Playing licks was an effective learning tool for many generations of early jazz musicians--for many, the primary way to learn was playing along with records and learning famous solos.) Now, you have a single II-V-I exercise that is allows you to practice (a) a useful lick that incorporates an arpeggio, (b) type A and type B voicings, (c) voice leading, and (d) left-hand comping rhythms. This is a high-yield activity.
2. Practice minor ii-V-i's in all 12 keys with licks
Do the same thing as above, but with minor ii-V-i's in all 12 keys, with a lick in the right hand. When you voice these, you don't use the 3-5-7-9
of the half dimished chord. Instead, voice it as a dominant 7th chord a major third below. For example, if you're playing a ii-V-i in C min
(| Dø7 | G7alt | Cmin7 |
), use your A-B rootless voicings for | B♭7 | G7alt | Cmin7 |
. When writing your licks, give some thought to which scales you want to use. For example, if you're studying melodic minor, one way to put that theory into practice is to use the Locrian ♯2
mode over the ii chord. Sticking with the C min
example, this would mean using D Locrian ♯2 (D E F G A♭ B♭ C D
) in the first bar over Dø7
.
3. Learn a song
A crucial skill as a jazz pianist is having a broad repertoire of songs that you know. Start expanding that repertoire now and make that a regular part of your routine. Always learning new tunes reinforces the more targeted/isolated practice you're doing. Start out by choosing a famous jazz standard that you know from a recording. Learn it in the traditional key given by the fake book. Use it as a chance to expand your harmonic and melodic vocabulary: pick 3-4 new voicings that allow you to voice lead a part of the melody with your chords. Play through the melody, and then practice improvising. If you want to practice arpeggios and scales in the right hand, it will have more value in the context of a song. Make it more interesting by mixing up the two: play four ascending notes from an arpeggio, and then 4 descending scale tones. You can vary the direction (e.g., descending arpeggio, but ascending scale, etc.) and order (e.g., ascending scale tones followed by descending arpeggio). You can also use the song as a chance to learn a new scale. For example, I recommend making your first song an F blues like Billie's Bounce. You can use a play-along if you'd like. Use head phones and take out one of the ears to remove the piano already on the track.
A lot of the other things you've mentioned will come naturally/with little additional practice if you focus on (1) and (2). After you master these (might take a month or two), I would replace (1) and (2) with:
(4) learning two-handed Type A and Type B voicings
(5) learning a bebop head in all 12 keys (play melody in both hands)
(6) learn additional voicings3 with new licks
1 Here's the rootless Type A voicing (a la Bill Evans) for a major II-V-I:

2 Here's the rootless Type B voicing (a la Bill Evans) for a major II-V-I:

3 You could start with some stacked fourths voicings (a la Chick Corea, McCoy Tyner, and Herbie Hancock), or any other voicings you want. If you want to focus on two-handed voicings, I've put together a partial list of the various types here.