An option I considered for proper space opera travel was something like:
- All long-distance travel is via warp drives. Warp drives don't function very near planets (say, 10 diameters or so), and their speed depends on local gravity, so it's fast sublight travel in the inner system, becomes ftl between stars.
- Ships in warp are surrounded by a warp bubble (10x ship diameter or something), which significantly protects from long range fire. Warp bubbles can merge, resulting in short range exchanges of fire or even boarding actions.
- Warp bubbles cause localized adjustments in the laws of physics that prevent inconvenient technology from working, such as nuclear weapons.