Played this again recently.

Homing Flame also works decently for clearing bullets, although it's more helpful with 2 players so that one person can use a more 'standard' weapon to damage stuff with. Otherwise yeah, in Expert I usually cheap out and use either Force + Flame for the damage of the explosive shots or lightsaber and play defensively.

The whole 'you have to change weapons when you see new weapons' sounds fun, will try that next.

Have you ever tried the Japanese-only Game Gear port? I remember seeing a copy for super cheap in a dollar store years ago (I have no idea why the dollar store had a sale of cheap Game Gear games including Japanese imports but I saw it and couldn't resist, it looked cool). The ship level's been replaced with a super-lame level where you just ride in one of those giant mechanical walkers and shoot lasers constantly in a long corridor (right before the core fight). Still, seeing the changes is interesting, and it's a good port considering the much less powerful hardware (and you don't need to know Japanese to play it) compared to something awful like the Streets of Rage 1 Game Gear port (nearly unplayable IMO).

What part are you having trouble with? Expert's certainly hard (the spaceship segment in particular) but the lightsaber and grenades still tear through everything. That, and throwing enemies when possible (like Orange, etc, who take more damage from being thrown into a solid object than being thrown offscreen). Remember you can always guard (in on-foot stages) if there's an attack that you find hard to dodge (hold attack + jump at same time when on ground to cover your face).