Wow, that's sad to hear. I've always found them to be very helpful and courteous. I'll be back in the UK sometime this year and need to get a shoe resewn so I guess I'll find out their level of interest then.
In my experience Tricker's are always an "interesting fit" especially if you are changing the thickness of socks. Adjusting with different thickness and lengths of insoles is all part and parcel of getting a comfortable fit. I just bought some Stows and am fitting some full length insoles for summer wear. and will likely switch to a half-length insole for the winter.
The frequency of conditioning is going to depend on a number of factors. I used to work in wet, muddy winter and dry, dusty summer conditions which meant I was conditioning 2 to 3 times per year. Probably best to condition them if they are looking a little dry or after you clean them again with saddle soap. Conditioner should soak through a thin finish of old, worn polish. Always best to apply the conditioner, let it soak in and then apply new polish
Pretty much that is all that is required, but just when needed as you don't want to over-condition the boots by applying too much and too often.You can apply some polish after the conditioner has soaked in to cover scuffs and add something of a shine if required. If you are going to be wearing them in wet conditions that a waterproofer could also be applied once in a while
It seems that you have figured it out, but ...That is pretty much what saddle soap does as it strips off the old polish and tends to dry out the leather. Applying multiple light coats of conditioner and letting it soak in for a time between the applications will help the leather greatly. I'd never use saddle soap on anything other than work boots and I haven't actually used it for for years.