Chappy,
Only you know what you want to build and how you want to approach building that. Only you know your own experience with tools, as well as the opinions you have formed about tools.
Here in FOG we also come to the use of tools with varied backgrounds, desires and facilities.
Festool is a system. In an ideal world every Festool customer would be within an easy drive of an experienced physical dealer. I have considered myself blessed that for more years than either of us care to admit Jesse Barragan has been selling me fine woodworking tools and machines. Many years ago he opened Eagle Tools, now of Los Angeles, CA. Jesse has surrounded himself with experienced woodworkers on his staff, as well as a vast base of satisfied clients. We all welcome folks new to woodworking and Festool.
Fortunately those who do not live within a realistic drive of a Festool dealer have the services of Tom and Bob.
My suggestion is to do what is necessary to make use of the experience Bob and Tom have with all kinds of tools, especially Festools.
I do own a TS75 in addition to a trio of TS55. Honestly I hardly ever use my TS75, but a skilled cabinet maker working with me considers his own TS75 his basic plunge saw, so he uses mine far more than I do. We each work in different ways and have different body shapes.
From the late 1940s until the Kapex reached the USA I had made a lot of money with many kinds of radial arm and miter saws. I still own and use a very large RAS as well as a smaller 10" miter saw. Yet I was so impressed with demonstrations of the Kapex and word from friends in Europe that I placed an early pre-order. Currently I own 2 Kapex and a fellow working with me owns another. I had made face frames before I owned a Kapex, but since learning to use mine I would not try doing so on an ordinary saw. Still, I agree that even with your generous budget, there are many Festools I would buy ahead of a Kapex.
You will need a plunge saw and a plunge router. It is best if they can use guide rails. For sure you will need a CT. I have owned CT22 since 2006 and we just received our first CT36, which is about the same size. You will save money with a CT36 because for nearly the same price the bags are larger. That might not be a factor in a hobby situation, but needs to be considered when used for business.
I believe in the Domino, and even more so since the introduction of the 4mm Dominoes. We use those joining plywood as well as solid wood cases. I always suggest buying the accessories for the Domino, especially the assortment of Dominoes along with the cutters. Later you will buy Dominoes in packages. Having the Sortainer is very convenient, ensuring you always have the cutters and Dominoes handy.
Basic to making furniture and cabinets is sanding. The Festool advantage is the freedom from dust in your work space and the extra life you get from your paper. I own virtually all the Festool electric sanders and expect to but the RO 90 when it is available. Starting out, you might be happy concentrating on 5" 125mm paper. Later if you need extra power you can add 150mm sanders.