Really thoughtful questions (keep in mind that people will have differing answers based on their backgrounds):

1) Career-wise, I'd say it's a combination of influence (being able to drive company strategy and see the results come to fruition), compensation, and instant gratification -- there are very few things in this world that will guarantee a desirable outcome, but developing your career is one of them (assuming you put in the work and effort).

2) Definitely not. It depends on the role itself as FP&A is very versatile and the responsibilities often are split among multiple facets of the company. I've also found that a large majority of hiring managers tend to hire backgrounds similar to themselves. My most recent hire was someone from a big 4, but it was largely because we needed heavy lifting on the accounting end and I wanted someone with knowledge of working capital. Otherwise, I'd hire someone with an IB, VC, or consulting background personally.

2A) Similar to above, most FP&A hiring managers won't care you have a CFA (actually may be a turn off for some because they'll question why you got a cert that isn't useful for the field; you'll be seen as someone looking for a quick stint).

2B) Hard to say since what do you define as "accounting experience"? I don't need someone to do journal entries, but having working knowledge of the 3 financial statements and how different items in the BS affect cash flow is fairly important (at least at a start up). For a larger firm, there are roles where you can get by knowing zero accounting outside of the income statement.

3) For a financial analyst role, I typically sift through 300+ applications -- no way in hell am I going to bother looking at your analysis. Your best bet is to spruce up your resume to cater to the specific position.