I think there should also be some kind of width limit as this is what inconveniences other passengers (fat spillage onto someone else's seat!) - they could have a guide at the gate a bit like the one for luggage and if you don't fit you pay for an extra seat or don't travel. Although of course extra weight costs the airline more so on purely financial basis this is the best gauge for them.
I would agree with the suggestion that he gets a part time job to subsidise his social life. By all means give him a small allowance towards travel and course materials but from my experience give him too much and he will never learn the value of money. And don't listen to him saying working would not give him enough time to study; I worked 16-20 hours a week during term time (full time in holidays) on a science course with up to 25 contact hours per week and still came out with a 1st class degree. The only exception could be medicine but I presume that is not the case when he is in Penrith.
Cheap, yes but certainly not cheerful! You are constantly bombarded by sales messages by staff who if they don't sell enough end up on very low wages and it is horribly cramped. If anything happens then they provide nothing; I was diverted to Valencia on a flight to Madrid where we sat for 2.5 hours on the runway and they would not even sell us water let alone provide it. Two weeks after I also found out that they had to request an emergency landing at Valencia because they do not carry sufficient fuel reserves. Cheap flights can't last forever though so you better enjoy them while you can!
Looks like snow is going to be more of a problem than very cold weather this week . Yr.no does seem to be a bit more optimistic than SMHI but I would prefer to expect worse than it turns out to be (maybe that is the dour Scot in me). The Swedes, in contrast to Brits, seem to almost overdress for running with long running tights even in the summer.
Seems like there is quite a few of us in Sweden! Ryanair is particularly handy for me as only 50 mins from Skavsta but flying with them is a horrible experience.