Yes the thermarest chairs are brilliant cycle touring. At the end of a day in the saddle, you can actually flop down and relax in them, just like the sofa at home.
Problems with Presta valves are not a problem with the valves. If the inner is seated properly so the valve (without the little nut) sticks through the rim at exactly 90 degrees, it's very, very rare to have problems with them shearing off. If in doubt, whip the tyre off and reposition the inner. (Unless of course you bought those stupid tyres that are a bastard to get on and off.)
Puncture resistance in tyres is an over rated quality when touring. When you're commuting it's different: you often have a schedule, the roads are covered in crud and stopping in some areas is ill advised, especially if you're just given some 'feed back' to another road user. But punctures when touring are pretty rare. I think I've only had a couple of punctures while touring in over 30 years. It's certainly not an abiding memory of our time away. I certainly wouldn't buy a tyre that was either uncomfortable, or sluggish, or difficult to fit, just because it was 'puncture' proof.
Trangias were a great revelation in the 70's. After the frustrations with paraffin Primus stoves, the simplicity and cleanliness of the Trangia was a revelation. Everyone bought one. But the love affair didn't last and for almost every cooking need there is a better alternative. The only exception is if you are baffled by the complexity of using an on/off knob or can't be trusted with anything that gets really hot. Gas stoves are way better for touring. It's easy to get the fuel, they're far more controllable and can be matched to proper cookware. A decent non stick, Teflon, 8 inch, deep frying pan isn't too heavy, (especially between two) and when mated with a two litre pan and lid (for boiling pasta, etc) allows you to cook almost anything. (pancakes, steaks, moules mariniere, etc).
Proper wine glasses are essential. It's easy to find ones that fit snugly inside the original shaped thermo mugs. Drinking wine from plastic is beyond the pale.
A large sheet of that blue poly tarp is really useful. You can use it underneath the tent as a groundsheet protector, but also for lunch time picnics, on the beach, improvised cooking shelter when its pissing down, etc.
A few proper clothes pegs and a long, long length of thin twine really makes a difference to getting stuff dry.
A couple of strong bungy cords.