I am highly opposed to this as the area next to the toilet is often the wheelchair space,
On what trains? Not on Electrostars because a wheelchair next to the accessible toilet would block the aisle to the next carriage so the wheelchair spaces are the other side of the doors in the centre third. I am surprised if any UK train is wide enough for accessible toilet + aisle + wheelchair.
A bike against the window opposite the accessible toilet does not blocks wheelchair access (which is mainly from the front) or the aisle, but it does take the single corner seat out of use. I am sure that was a tip-up seat on some previous train, either an Electrostar pre-refurbishment or the Network Express 365s.
Best would be some European-style "multifunctional" carriages with lots of tip-up seats so each 4 car unit can accept more bikes and wheeled passengers off-peak than are ever likely to board, with still plenty of seats or standing room for peak crushes. But it seems like no TOC is heading that way. Greater Anglia now have bigger multifunctional spaces on Flirts but at most 3 quarter-carriages in a 12-car 745/1.
nor do I wish to sit near the toilet at all,
Yes, well, as even this thread makes clear, there are many people who wish people with bikes not to sit on the train at all, so I will tolerate a bad space over no space. And I only need sit where I can see my bike, not necessarily with it. I agree with much else you say.
Why would you want to cycle on the motorway? I have cycled on the A5 dual carriageway and it was grim, wouldn't do it again. All motorways have parallel minor (or major) conventional roads.
Not all of them do and you might want to cycle to get somewhere quicker that is not served well by trains or buses. It is very useful to be able to cycle over the M5 Avonmouth bridge and it seems very strange that there is no cycleway over the M25 Dartford bridge or the A14 Ipswich bridge. I remember reading somewhere about some other small M5 bridge near Bristol which has no cycleway over it and it has taken maybe 40 years to rebuild a former railway bridge which will cut many miles off the cycling journey between two towns. While these are usually noisy and not wonderful, motorway-side cycleways can be very useful.
In days gone by, when stopping trains between Royston and Cambridge, and Fen Line trains, had to be 4 cars, cycles were banned in the morning peak. Fortunately, with 8 car trains, that's no longer necessary.
And yet unfolded bikes are still banned from the Ely-Cambridge (inclusive) section between 0745 and 0845, no?
The bridge at Cambridge has gutters, and they are more trouble than they are worth. It is far easier to use the lift.
I have an electric bike: it is too heavy for me to push up a gutter, and the weight makes it difficult to control coming down.
Cambridge's wheeling gutters have been installed on the wrong (left) side by someone who does not understand that most bikes in this country have dangling gear mechanisms. So, you must either walk on the "wrong" right-hand side and ignore the tutting, or you risk expensive damage to your bike gears.
Cambridge North is quieter so less of a problem using the wrong side but the gutters are even more incompetent, installed too close to the sides, so your right pedal strikes either the side of the bridge (if down) or the handrail brackets (if up).
In a corect installation, electric bikes should be OK with walk-assist (up) or brakes (down) to stay in control, but maybe the lift should be used if in doubt. I do prefer escalators but some station staff in London get upset if they notice me using them: have they never seen the videos of places like the Rotterdam Maastunnel? I prefer to leave the lifts free for people who need them.
