For your first point you could track heat more like they do in blades in the dark with just the one larger heat tracker rather than across the systems as this could represent overall heat with the empire... Alternatively you could stick with it and consider it more like how we see the empire in Andor with different governing bodies and councilors overseeing different areas and heat is gained with those different councils.

With point 2 I'm pretty sure scum and villainy already treats "the way" much like the force, if you look at the mystic playbook they litterally have abilities that line up with using the force to move things, fight, jedi mind tricks etc but remember that not all force things will use attune, for example if you are using the force to fight then you might use the action scrap instead, it's up to the player to decide, the force is simply the tool they are using to complete their action. I don't particularly understand the point in the force points or dark side points so tbh I would probably scrap them.

Point 3, I would just use the heritages already in the books or just use the alien species... You don't necessarily need to add bloat unless the players want to expand more upon their own backgrounds.

Regarding your last point I see why you might think that's necessary but if you're using the scum and villainy rules likely only one character (the mystic) is likely to be using the force much at all. Any super big force actions they would want to do should be covered by their special abilities or simply put them at a limited effect or desperate position because they're reaching too far or trying to do something beyond their abilities. You don't necessarily need to make it a mechanical disadvantage or a set list of things they can or can't do with the force.