This entire argument is ridiculous because many other supposed "popular vote" states don't even have a freaking direct election presidential system. Some outright have legislatures elect their presidents still, and for most, the head of government is the guy who wins control of the lower house of parliament. I resent and reject any argument based on this ludicrous simplistic notion--what countries have a strong presidential system that elects based on a popular vote? Luminaries like Russia and Argentina and Chile, that's the answer! That's whose company you'd put us in by eliminating the electoral college.
Your argument rests that there is negative harm from having a popular vote election, which you have not demonstrated. As stated, the House of Representatives and the Senate more logically work to defend and advocate for local interests (as they are directly elected from geographically fixed ridings). How do not see how a change from the EC to PV would make a difference regarding 'suburbanization', or 'destroying regionalism', how? Just how does a 'swing' election for the President cause this? The President's powers in the United States are deceptive due to historical happenstance of the United States being a superpower.
Actually if you look to Canada, which elects the legislature that picks the Prime Minister, Canada's Stephen Harper is actually the most powerful politician in the western democratic world, moreso then the US President politically speaking, because there's virtually zero checks and balances to a majority government with a party as disciplined as the Conservative Party of Canada.
So arguing about a 'strong Presidency' seems meaningless when a) various other political positions can be described as more powerful and thus the stakes are higher, and b) the executive branch is constitutionally
co-equal to the judicial and legislative branches so I'm not sure what your getting at beyond the 'Imperial presidency'; which only applies to the US's geopolitical position not domestics.
Demonstrating that your concerns seem out of place, I have, taking a brief look at Wikipedia both Argentina and Mexico have observed to have popular vote systems and no electoral college in site, but have a political system seemingly similar to that from the United States. I do not think it likely that they lack 'localism'/'regionalism' uniqueness issuewise.