The offence is failing to comply with the instruction given by a prescribed sign not to proceed past that sign in those lanes. You admit that you did. The photos show that you did,
The offence is not "failing to make some kind of effort to move over to lane 4 before passing the signs", and as such whether or not the photos show you indicating has no bearing on whether the offence was committed.

If you tot up to 12 (or more) relevant points (assuming that you had at least 3 current points when the offences were committed, The court is required by law to disqualify you for at least 6 months, unless it finds that such a ban would cause excessive hardship (to you or others). The court is not allowed to take into consideration anything that makes the offences seem less serious - simply whether or not the ban would cause exceptional hardship.

It would seem that your argument as to why a ban would be far harsher on you than other people totting up is that due to your austism and OCD you are unable to undertake alternative work. As the hearing is in 8 days time, I assume that you already have documentary evidence of your conditions, and a letter from an appropriate medical professional to that effect?

If you are banned, the ban will have immediate effect - so don't rely on being able to drive home from the hearing.

There are 2 separate legal issues - the s. 172 requirement and whether or not the apparent failure to serve a NIP on the RK within the 14 days is a bar to prosecution for the speeding offence.
There are also 3 logistical issues - how the notice came to be sent to the "wrong" address, how the delay affects potential disposals, and the fact that we do not discriminate - I am as happy to ban able posters for posting rubbish as I am disabled posters.

The s. 172 requirement to name the driver applies from when the notice is served by being delivered to the addressee's "last known address". It requires the required information to be provided within 27 days of the date of service (presumed to be 2 working days after posting by first class post). There is a defence if it was not reasonably practicable to provide the information within that time and the information was provided as soon as was reasonably practicable afterwards. Whether or not you have a defence to the speeding allegation, has no bearing on the validity of the s. 172 requirement - you still need to name the driver, as soon as is reasonably practicable.

For practical purposes, it is unusual to be prosecuted for naming the driver "late" unless the 6 month limit for instigating proceedings for the speeding offence is rapidly approaching, but on the face of it you appear to have a reasonable "not reasonably practicable" argument.

A speed awareness course would generally be offered for that speed - if the s. 172 response admitting to being the driver is processed within 3 months of the date of the speeding offence.

The police get their information from the PNC which is updated from the DVLA overnight - so absent some major snafu, if your details were held by the DVLA as RK for that vehicle and that VRM the day before the police looked up the keeper details, they would have gotten your details. They would only contact a previous keeper, or search the insurance database, if no current keeper details were shown.

It is rare for the leasee of a leased car to hold the V5C. What is the date after the DocRef. No. at the bottom of page 2 of your V5C?

The truth is the first casualty of modern journalism.

What makes you think that there are rules?

Unless I've missed something fundamental here.

No. You have saved the OP from unnecessarily having to read the "READ THIS FIRST" sticky at the top of this forum. Gold star.

before I respond I just wondered if there’s anything on the notice or about the circumstances that I should be checking, or whether it all looks pretty standard?

No

Thank you for the brilliant ... summary.

If it was a brilliant summary, why do you feel the need to ask questions that have already been addressed?