Abortion and guns are different. Many rural voters own guns and personally feel a loss from gun control. The average rural voter has a basically libertarian bent and would probably be pretty happy with a truce that they are left alone about guns and women are left alone about abortion.
Like it or not the electoral map favors rural voters, Democrats can recruit more urban voters and it will make no difference for winning seats. If Democrats gave up 5% of their urban votes in exchange for 3% of the rural votes the Republicans would find themselves in the wilderness.
Depends on how those votes are distributed, in both directions, but I doubt either would make a huge difference. One thing to remember is that rural areas are less red than cities are blue. A 75/35 split seems to be the most common rural distribution, whereas many city districts are 90% dem with the GOP struggling to outperform the greens or libertarians.
The GOP stands to gain nothing in the urban cores outside of a few southern cities and Texan cities, but they currently live for the suburban fight. The Dems biggest struggle out in the sticks is less that they can't field any candidate that isn't an 80 year old union man or a local youngin' fresh out of college who says all the wrong things (and is thus unelectable).
New York City was 80/20, with Trump making significant gains in heavily immigrant neighborhoods: https://www.nytimes.com/interactive/2020/12/20/us/politics/e.... Trump won 26% in LA County. He ran within 7% of Biden in Miami-Dade County. The GOP absolutely has room to grow among working class Hispanics and Asians in cities.
Like it or not the electoral map favors rural voters, Democrats can recruit more urban voters and it will make no difference for winning seats. If Democrats gave up 5% of their urban votes in exchange for 3% of the rural votes the Republicans would find themselves in the wilderness.