There is nothing unsafe about people standing in the Euston concourse. It's not a Tube platform where they might end up accidentally pushed on the track. If it's full people will go elsewhere. I've never seen a crowd in there I would consider dangerous give or take the scrum when a train is announced, and I've seen disruption there many times.
It is about safety though - having large crowds, which just get larger creates a safety issue. Just because they're not next to platforms doesn't mean it isn't an issue. And you will soon back it up into the tube station as well for good measure.
Maintaining A service on those routes. It doesn't have to be the full service at the expense of less frequently served routes. It wasn't long ago that Northampton to Birmingham was 1tph.
Better to lop 1tph from 3tph than 1tph from 1tph, unless a genuinely adequate bus replacement can be provided (it can't on a 110mph railway[1]).
[1] I'd have no particular objection to canning Watford-St Albans to free up a crew as you can provide a genuinely adequate bus replacement.
Sorry - it does have to be at the expense of the less frequent routes - those routes are less frequent for a reason, either line capacity or demand.
Northampton - Birmingham was hourly for a short period of time, driven by the WCML modernisation which as I recall limited capacity at Rugby. In fact Silverlink (as it was then) were curtailed to either Northampton or Rugby and the Northampton - Rugby service was operated by Central Trains. It was as the modernisation ended, which I think coincided with the LM franchise, the service returned to being at least every 30 mins.
And whilst a bus replacement can't be all of the answer, nor was it yesterday when ticket easements meant passengers could also use EMT or Chiltern. The key to it is to look at where people are trying to get to and how that can be best served.
The reality, whether or not you like it, is for people trying to get to points north of the Rugby on the TV line, a direct train from Euston wasn't going to be offered as a solution given the other issues. And as I've already pointed out twice, but to do it for a third time does no harm and you might actually take it on board this time, the TV stations had the following alternatives:
Nuneaton - EMT to Leicester or Virgin / Chiltern to Birmingham or Coventry then XC or LM to Nuneaton.
Tamworth - EMT to Derby or Virgin / Chiltern to Birmingham then XC to Tamworth.
Lichfield - Virgin / Chiltern to Birmingham then LM to Lichfield.
Rugeley - as Lichfield.
Stafford - Virgin Liverpool services or Virgin / Chiltern to Birmingham and then Virgin / XC to Stafford.
Stoke - EMT to Derby and EMT to Stoke or as above to Birmingham then XC to Stoke.
Kidsgrove - as above, plus EMT or Northern from Stoke.
Yes - all of those meant extended journey times, but so did pretty much any journey on the WCML yesterday afternoon.
The ONLY TV stations left with a real problem were Atherstone and Stone. Neither are significant stations.