I think the club will aim to eclipse the capacity at Old Trafford. It isn't their mindset to be second best. We need to be bigger than United and the premier football club both on and off the field. Manchester is growing in population and economy and it attracts a whole new scope of people. United still have that historic attraction but it will not take much longer for people to be drawn our way instead. Certainly to businesses and hospitality.
Internally the changes do not have to be mind blowing. I imagine the plans for expansion are similar to those drawn up way back when. It is externally that improvements can be made. There is sufficient room to create something quite spectacular. From external designs that make the stadium incredible, to further facilities that enable people to stay in the area post-match and pre-match for longer to try and address current transport issues.
Whilst transport can be improved, you are able to walk into town in 20-30mins if you get a gallop on. I had to do it to get last trains to Sheffield when I was at Uni and managed it without leaving early. That's more than an 800m walk which is deemed sustainable in planning terms, but it isn't too bad. It is part and parcel of football to have issues getting to and from games but it would certainly help draw additional support if transport improvements were made. There is scope to improve things significantly without mind blowing investment.