Yes I agree BUT you forget this won't happen until said line speed is raised when the infrastructure has been upgraded as it's not usual practice for drivers to drive trains faster then the line speed otherwise there would be a lot having tea and biscuits
It won't take long at all, although actually being able to board a train will make a BIG difference as they can get very cosy!
As certain Class 365 fans here would say and they know who they are btw, the fleet does have air conditioning already, it's called open the window
I question your wisdom as to they look horrible, they're not here to win any beauty contests although GTR hasn't done them any favours by not giving them the TLC they need - with a bit of TLC they will be fine until the day they actually retire.
Bearing in mind the fleet has worked more then 42 years and on very intensive workings so it's no surprise they're showing it.
I look forward to the 313s retiring but not because they're old but because they are solid workhorses that are simple to operate and so deserve to be retired at long last.