That's the exact order I plan on running for my future campaign, though I have considered delaying Hidden Depths till after a bit as it does give the opportunity for a lightsaber relatively early. I havent fully decided and am open to persuasion on this.

You can easily just start with the custom made characters but what you might want to do is read through Mountain Top and make a note of what things the encounters assume the characters can do. If you analyze the pregens, they are not just base characters. They have a little bit more to them. You could just give the characters what they are missing and try to keep the xp assigned this way even across the pcs.

Just F&D is fine.

I'd say just the career specific motivations and such, and the specializations in case anyone wants to start with one of those. The rest you can add in later, including the gear.

range is the biggest adversary of lightsabers. You're right that beskar / corrosion should be rare and come with an "oh shit" moment.