Just finished work so haven't seen the problems, but I believe whilst there is no fix all, there is certainly plenty of solutions to cut through the waffle for a high proportion of journeys.
TOC only tickets should remain for reasons outlined, people have coped with planes for decades like this, and it's not alien to bus travel either.
Ticket types need to be chopped down and simplified for the sake of us staff as well as customers!
So I'd propose 2 tiers of Advance tickets.
Off Peak and Anytime Day tickets
Off Peak and Anytime period tickets which are 1.7x the day ticket equivalent.
First Class fares calculated to 1.6x their standard class equivalent.
7 day seasons priced as 5xAnytime day returns
14 day priced as 9xAnytime day returns
28 day priced as 17xAnytime day returns
But, priority is to remove rubbish such as below:
No first class fares 3x or more the standard equivalent.
My company (XC) are guilty of selling Off peak period returns but no Anytime equivalent on a lot of journeys, it's ridiculous and needs to go.
All TOC restrictions should be listed under the route. Peak and Off-peak times are the same whether travelling in Ayrshire or the hell-hole of London, just change the prices as necessarry to get similar revenue using the formulae above.
It's not a cover all, but we need to cut through a lot of the rubbish that exists and feeds this media led paranoia.
So would you allow day tickets for massively long journeys, or would people doing long day returns still have to split tickets? It's more complicated than it looks.
The tickets I used most under the old BR system were
Cheap Day Returns
Off-Peak Travelcards
Supersavers
Network Awaybreaks
Peak Travelcards
Advance-booking
In that order. I haven't done any research, but I'd imagine that all of them got a lot of use. Having a two-tier saver/supersaver system helped spread demand and vastly reduced the need to split in various places. The Awaybreak just happened to be quite convenient.
I like most of your ideas, just I happen to think that BR restrictions and BR structures worked very well, so I'd modify it a bit.
So I'd propose
- 2 tiers of Advance tickets.
- Off Peak and Anytime Day tickets
- Off Peak and Anytime period tickets which are 1.7x the day ticket equivalent.
- Super Off Peak period tickets which are 1x the OPDR equivalent, but not available on Friday and during the peak shoulders - to avoid the need to split tickets, especially for long-distance weekend pax - such as cranks.

- First Class fares calculated to 1.6x their standard class equivalent - might ignore the third, 1st supersaver sounds a bit silly.
- TOCs would be free to include limited promotional offers, Rovers, Weekend First and an Awaybreak equivalent being possible examples, provided they don't do loads of them.
- 7 day seasons priced as 5xAnytime day returns
- 14 day priced as 9xAnytime day returns
- 28 day priced as 17xAnytime day returns
I like the last three, they seem very fair for regular passengers. This would also be part of a ten-year fare freeze, to allow inflation to catch up, and regulation of all fares, not just currently regulated ones, so that off-peak travellers don't get squeezed. Fare restrictions would be returned to as near as possible what BR did in the 1990s, so no restriction for return portions of off-peak tickets during the peaks for instance. It's pointless to have London day-trippers sitting around for hours while all the commuters go home.