Touring Tyres / Touring Tyre Size

I would not limit yourself to 28 mm + guards, leave room for 32 + guards and you can always run 28 mm tyres but have the option of upping the tyre size if needed.

I did'nt really mean max 28 + guards TBH. Just that, thats who you'd likely buy an OTP. One massive bonus with having room for 32mm tyres, is number of tyres you can choose from. Especially if you want a lot of puncture protection.

I'd consider anything upwards of 32 as trekking tyres (IMHO).