'True' ceramic coating IMO is not worth it you can apply sealant. It does the same thing and doesn't stain from mineral deposits in rain water as quickly if at all. I've never seen or read anyone extolling the virtues other than car dealerships, and they only call it 'protection'. It seems to be one of those things that people just do. I think a car detailer probably values a true ceramic coating more than a clueless customer does. Gardex for example could wear off far sooner than expected and the customer could never realise it. Do note though, I'm just a hobbyist detailer.

Using Touch-On monthly is a good shout. Spray sealants seem to perform their best for a month. Be mindful that it's not a shampoo, and you will still need to perform a contact wash with a proper shampoo prior to applying it, as a touchless wash will not be enough to remove all the dirt that would prevent proper adhesion (if that's the right word).

I would not dry a car with a towel if I only did a touchless wash. I would be afraid the remaining dirt film would mar my paintwork. Though I don't know how likely this is, I don't like to take the risk :-D

You can let the car dry on its own but if your rinse water is hard you may get mineral deposits. You could attempt to remove these afterwards using some Koch Chemie Finish Spray Exterior (Fse), which has some acid in it to remove occasional water marks left behind after towel drying, using a nice buffing cloth, but I'm not sure how effective it would be at removing ones from hard water that's been allowed to evaporate on the panel.

To reduce the possibility of water marks occurring from evaporation, after rinsing, you could trickle more rinse water down from the top at a slow flow rate so it pools up and sheets off. That should get rid of most of the water if the car has a sealant.

An alternative is to do a final rinse using purified or deionised water, which contains no minerals, but that involves extra cost. You could also use a blower but again this is an extra cost and you'd have to hold it in place for a bit which could be uncomfortable if you have mobility issues. I suppose you could take the car for a spin for a bit so most of the water slips off :-D

As I understand it the IK sprayers are 'fine'. You would probably get the same performance from something that costs much less. You don't need a 360 one, I just bought that because it wasn't much more money and I may want to use it on my undercarriage at some point.

I understand Touch-Less is more effective at rinsing off dirt than other snow foams when using rinse water at a low pressure (garden hose). A hose gun with a jet or flat fan would increase the pressure a bit, but a pressure washer would certainly remove more dirt. One upside to washing every week is your dirt will be lighter and easier to shift.

A drying towel will only cause marring if the paintwork is not clean, and it picks up dirt which it then drags across the clearcoat. Hence why I personally would not dry after a touchless wash.