What to do about this is a real problem. If the players walk off this amounts to a 'win' for the idiots in the crowd who boo and chant in order to be provocative. If the officials call off the game then that is also a win or the players being booed get blamed and the booing gets worse next time. You can't ban home fans without banning away fans otherwise you're just asking for trouble. You either play behind closed doors to protect the players, play in a neutral venue or play both legs in the home country. The power is in the hands of the national FA's and UEFA need to be working with them to understand and combat the issues in the specific countries. If the national FA refuses to accept the problem or can't ticket games to weed out individuals then they can't host international games.
With regards to England we were good without having to excel. I think Mings and Winks did OK but there was a lack of consistent quality in midfield. Rashford is in serious need of a decent coach - I think he's gone backwards since he made Demechilis look a mug. If he was half the player Hoddle thinks he is he'd be twice as good as he is.
But overall a very professional performance in tough circumstances.