The route changes will lower costs - they will also of course lower revenue, and it's a case of whether they've got the balance right!! The risk of a reducing PVR is that whilst driver costs should come down, overhead costs remain the same (depots, managers, supervisors, schedulers etc). I'm not sure why reliability and fleet presentation will improve with a smaller PVR - unless they keep the same number of cleaners etc, thereby contradicting the objective of reduced costs!!
Closing Braintree is probably inevitable - I think it's only about 6 vehicles now anyway. Merging Clacton & Colchester is a non-starter. They're a long way apart!! The inter-urbans could run from Colchester, but I suspect such a merger would spell the end of the Clacton local network. Basildon and Hadleigh are closer, but traffic congestion in south Essex is horrendous, and the unreliability and extra drivers hours and miles you'd incur would probably make this a non-starter.
It will be interesting to watch, the depot changes are just speculation of what could happen, before First would even consider abandoning the operation. However, First Essex have been known to close a network down along with the depot as they did in Braintree, but it would depend on how much the network contributes to the overall business. As I understand, the income from the Braintree services didn't justify the investment in the depot, and with the 70 being rationalised, the case for the Braintree outstation to remain becomes weaker.
Some back office staff are being reduced, such as controllers and supervisors, but not engineering or maintenance staff. I would expect reliability and presentation to improve even with a PVR reduction, as depot staff will have time and capacity to complete more preventative maintainence. Also some of the most unreliable (and unappealing) buses will be scrapped. The situation where PVR can't be made or where no spare buses are available to cover breakdowns, as is often the situation now, is certainly not sustainable. Whilst the PVR reduction won't help vehicle reliability and presentation long term as vehicles age, it will fix an immediate problem. Who knows, some of the cost savings may even be invested to refresh mid life vehicles, as they are doing with the route 100 vehicles!
Most of the changes I have seen are route changes, rather than reductions, so I wouldn't expect revenue to drop dramatically. The 41 will be covered for most of the route by 2 other routes and the same applies to the 72. Limited areas will be left without a service, namely a small part of the Chignall Estate in Chelmsford and a small part of Witham. In fact, some areas are receiving a better service! I'm not familiar with the north and south Essex town routes, so i'm not sure what impact there will be in these areas.
The challenge for First (which they haven't been proactive about so far) is to ensure the route changes are communicated well to passengers. Hopefully the communication will not be limited to a web article and social media.