A few miscellaneous points, if I may, to correct and advise on a few matters.
Firstly, with regards to rolling stock. Older rolling stock may need to have door controls activated or installed to allow a driver to operate the doors. Some of the mentioned stock has had cases where this has been done already, a long time ago, such as the 455s which operate in a green colour on Southern (and, interestingly, these particular units can all be controlled by either driver or guard). Unfortunately it is not actually terribly hard for door controls to be changed on a lot of stock - where the DfT has a will, usually a way will be found, even if it's not desirable for passengers or staff. You also need a way to monitor the doors - as shown by the installation of Driver Advisory System screens in a lot of rolling stock (tablet-sized screens which show eco-friendly driving and schedule information) it is also not too difficult to build in door monitoring displays, whether connected to cameras on the train or platform (the latter being how the Tube has been operated for many years).
As for technologies to alert signal boxes when things go wrong - do not rely on the signaller being able to provide useful advice or support immediately in a format which would be accessible to passengers. I have been involved in a few incidents recently, such as fatalities, trespassing and major signal failures, where the signaller and TOC controllers were too rushed off their feet in protecting the lines and deploying resources - and so on - that they were unable to provide any usable information to drivers of full-and-standing trains immediately affected by the problems. That is to say, trains which were stranded. In one case, the only message that was provided for something over half an hour was "somebody has stepped in front of another train", to a rammed-full service stranded on a railway line in the middle of a field with little phone signal. Some of these trains had very close calls with people attempting to use egress handles to exit onto the track or into other unsuitable locations. I would rely far less on the signallers (and, by extension and despite general willingness, drivers in the area) to be able to give understandable and location/traction specific advice to passengers on a stranded train, even if they are aware there is a problem of some sort with it. These were in areas with similar, if not almost identical, resources that SWR services would be controlled by.
A lot of conductors/guards etc. (less so intercity-style Train Managers) to whom I've spoken have expressed fears about job security in the next few years. Depending on your financial background and commitments, a guard's salary may not lay much basis for saving any form of significant sum for future uncertainty. Many are reasonably comfortable with their current stable income, but would be very worried indeed without one, as with many jobs out there. This is one of the biggest factors I am seeing with guards moving en-masse to making job applications for driver roles. A lot of talented conductors and guards could have been retained, perhaps even with enhancements to their roles (such as better equipment, fault finding abilities, professional development, etc.), had this not come into play. Admittedly my knowledge and conversations have mainly been around the south of England, but I should imagine the same applies equally in the north, east, west, and perhaps in parts of Scotland.
Because of these fears over jobs, and previously a culture of apathy towards the role in some geographical areas, staff may not be motivated to do their jobs properly, such as patrolling trains. Problems with visibility of staff do happen on SWR as well as anywhere else, and knowing the job as well as I do, I will not take it from anyone that performance does not need substantial improvement. However, I can also see, in equal or even greater measure, why staff sometimes do not feel encouraged to do what they should, and in some ways I fully sympathise. That being said, SWT generally had better morale than, say, Southern, so it is a bit of a mystery sometimes. It is not uncommon for the guard to be invisible on the train, wherever they are in the country. Things like staying visible and proactive whilst still being able to walk back to door controls in the back cab, or moving between units, are entirely possible with a bit of planning, and I can vouch for this on a personal level.
Because the general public do not (with the exception, it seems, of Wales) generally understand the scope of responsibilities which the guard has, staff do need to patrol their trains and show they are of value. This was one of the pitfalls with any TSGN franchise holder (whomever it might have been) trying to get a better deal from their onboard staff; and I have heard this from some surprising and indeed influential characters in the industry. Southern conductors in certain areas had developed habits of dispatching from the back cab or staying in one position, never taking commercial equipment, not looking out for passengers, never being seen on late night trains and so on. The shining stars of the onboard crew world (of which there were equally many) were let down by this, which dropped morale and meant that when job changes were introduced, the onboard wellbeing of passengers got worse rather than better, as well as the underlying safety issues of DOO.
Unfortunately, on my personal travels, I see visible and invisible guards on SWR in equal measure. I fully appreciate that even the invisible ones will have been tested and proved competent on what to do in an emergency, and I'm not saying they wouldn't do what's needed of them. But in order to retain responsibilities, job security and a permanent presence, all need to pull their weight. Again, I know this is not easy, and I can again sympathise with people who find railway shifts hard, dealing with the travelling public on a 24/7 basis. But there are perks to doing the job properly.
