Need help understanding the Battle Pass

I'm a bit confused of how it works currently.. but just to make it quick, here are so some questions:

• is the XP I gain in matches "only" the XP that counts in the BP ? There's no certain BP missions like Apex Legends for example ?
• Conten Creators said that I'll be able to choose which BP road I want to level.. but for some reason I couldn't and it's going sequentially, am I missing something ?
• I calculated the BFC I will be getting from the BP, they're 1,500BFC, is that correct ? That means I'll be able to buy the next BP without buying more BFC, right ? Also how many free BFC do I get with the Premium BP ?
• Does BF pro gives me more cosmetics than the Premium BP ? I couldn't find any.. tho it says exclusive content ?

Oh also something not related to the BP, but for some reasons the challenges they said they changed or reduced in this patch.. didn't get reduced for me ? Is that a glitch ?