No idea on feasability of adding in that to an existing building (unlikely is my guess but i'm not an architect)
And yep. There's escalators at some grounds - eg: Spurs. (and the O2 , and Wembley) which is nice.
But most have stairs.
There actually are lifts in the West Stand but they are...
The premium wide steps - round the way - are for AMEX card owners only ! Have you seen them ? :)
And what about the lift ? i think its a tenner a trip.