Statistics show that there will be very little need for stellar demolition for star highways.
In our region of the galaxy the stellar density is about 0.004 stars per cubic light year. The density is higher in some galactic regions and lower in others.
Suppose that a galactic highway is going to cross the entire diameter of the galactic disc, 80,000 or 100,000 or 120,000 light years. Suppose that if a starship using FTL drive passes within 0.000001 or one millionth of a light year of a star it will suffer bad effects from interacting with that star. One millionth of a light years is about 5,878,000 miles.
The proposed star highway will have to be a clear cylinder of space with radius of 0.000001 light year and a height of 80,000 or 100,000 or 120,000 light years. The formula for the volume of a cylinder is pi times the radius squared times the height. One millionth times one millionth is one trillionth.
The proposed galactic highway will thus need a clear volume of space equal to 251,327.2 multiplied by one trillionth cubic light years, or 314,159 multiplied by one trillionth cubic light years, or 376,990.8 multiplied by one trillionth cubic light years. And if you bother to do the math you will find that the total volume of space occupied by one trans galactic space highway will be less than one millionth of a cubic light year.
Suppose that FTL ships need a much greater radius of clear space to operate well. Suppose that they need a clear radius of one thousandth (0.001) of a light year, or 5,878,000,000 miles, for safe operation.
Thus a trans galactic highway 80,000 light years long will have a volume of 0.213274 cubic light years, a trans trans galactic highway 100,000 light years long will have a volume of 0.314159 cubic light years, and a trans galactic highway 120,000 light years long will have a volume of 0.3769908 cubic light years. Since there are about 0.004 stars per cubic light year or about 250 cubic light years per star, there would be about one star in over 500 trans galactic highways 120,000 light years long.
Actually the galactic disc is about 1,000 or 2,000 light years in thickness. Actually the galactic disc doesn't have a sharp edge, as you travel higher and higher "above" the galactic disc the star density gets less and less and less. At distances a few thousand light years "above" or "below" the galactic disc the stars are very thinly spread compared to in the galactic disc.
So a logical form of galactic navigation would be to travel straight "up" (or "down") from the departure solar system until the star ship is several thousand light years "above" (or "below") the galactic disc. Then aim for a point in space several thousand light years "above" (or "below") the destination star system. Then travel 10,000 light years or 50,000 light years or whatever the distance is to the point "above" (or "below") the destination star system. Then head vertically "down" (or "up") to reach the destination star system.