Hi Amanda, I know how you feel, it does seem so much simpler when they're on set timings! This should be achievable at 22mo, we certainly did set timings from when our DS started with his childminder at 11mo, although we would always adjust BT if he'd had a bad nap. However by 2yo or thereabouts, we wouldn't bring it forward by very much on a bad nap day, half an hour max, usually only 15mins though, that just worked for us.
You're probably still coming out of the 18mo sleep regression, right? We found the key to this was to realise a jump in A times and work with that. As you note, it's very hard to say what is a good routine for a 22mo as they are all so different. Yours looks quite reasonable to me, I would suggest you go with it for a week or so and just see how he responds. I would also suggest increasing that last A time to BT a little if it takes him half an hour to get to sleep, unless you really do know that it will always take that long no matter what you do - but you may be surprised! Note that this could either be keeping the same nap length and a later BT, or by capping the nap, say to 2h (note you don't have to cap to 2h when it's only one nap, but eventually you will probably have to start capping), and actually probably then keep the same A time to BT, but he'll be more tired as he had the shorter nap. On the question of nap capping vs later BT, we found at this age that he needed at least 10.5h at night otherwise he was too tired the next morning, however as he got older he is optimum night sleep increased. You will see how it is for your DS over time...
So give it a go but you'll still need to be ready to adjust your fixed timings if something's not working, use his response to figure out what that change should be, and by all means post on here so we can all put our heads together with you
Btw I could never tell OT or UT by this age, I'd have to look at his behaviour over the course of the day to figure out how to change the set times. Hope you're able to relax more soon, I remember this age was so confusing for me!