I don't think there is capacity to stop EMT services on the already busy MML South route at St. Albans. Also is the demand even there? St Albans already receives fast services to/from London and I don't think there are many passengers wanting to travel further than Bedford from there.
Indeed St Albans gets 2tph non stop to St Pancras Int, 2tph that only stop at West Hampstead Thameslink and the remaining 6tph are a mix of semi fast and stopping services so 10tph is more then enough capacity.
I rather they continue to serve Bedford/Luton/Luton Airport Parkway alternately like they do at the moment eg Luton Airport Parkway - Bedford - East Midlands stations or Luton - Bedford - East Midlands stations.
We already have a slow Nottingham call at Luton Airport Parkway and Bedford so why not consider a slow Sheffield calling at Luton then East Midlands stations?
Firstly, everything (current) is inferior to the first class interior of an EMT.
That is your opinion but you're comparing apples and pears eg comparing the 1st Class of a EMT service to Standard Class so of course they're going to be different, a much more fairer assessment would be to compare 1st Class on a EMT HST with 1st on a GWR/LNER/XC HST for example or even compare Standard Class on a EMT HST with Standard Class on a GWR/LNER/XC HST etc...
Who's to say that new rolling stock won't be a suitable replacement for the HSTs which although are a good design deserve to be retired after decades of service, people moaned about the Class 80Xs saying there be less legroom but that was proven to be utter twaddle.
But if they're insane enought to go for Hull trains' 180's, then the replacement is not only less comfortable, but can barely complete a diagram without breaking down. That is doubly inferior.
The issue with the Hull Trains Class 180s is not the trains themselves but rather with the suspect maintenance that Crofton carry out on them, as has been said before Old Oak Common had them performing well as they were used to the quirks and knew how to get the best out of the units but since moving to Crofton that knowledge has been lost.
To give a analogy, when the Class 700s started working on the GN there was various issues as the drivers were still getting used to them compared to on the TL where the drivers having spent longer with them were far more used to them and knew various tricks to get the best out of them, the same applies for the maintenance of the Class 180s.
As to assuming that the Class 180s are less comfortable then again that is your own opinion and not a balanced one, I've used the Class 180s a number of times with Hull Trains, Grand Central and First Great Western yet to have a uncomfortable journey especially as there is nothing that a decent maintenance team can't do with them.