I'm either wrong or your company is a (welcome) anomaly. I'm happy to be wrong.
Don't get me wrong, not every good SE will be good at sales - as you say there is a magic element to being great at sales - generally it is the non technical people who make this move. The more technical ones like me go down the product route.
* Are persistant and laser-focused on getting deals to close.
* Can turn off every part of their brain that would prevent or delay them from asking for the sale.
* Have a nose for the org chart and for figuring out who needs to be sold to how.
* Can accurately gauge where they are in the sales process for any prospect, engagement, or eval --- this rarely has anything to do with technology and usually has everything to do with budgeting, MBO's, and getting bakeoffs started.
* Take meetings and make visits relentlessly.
* Appear confident, like the guy-in-the-rated-R-movie.
Most of this isn't helped by product knowledge, and some of it is actively hindered by in-depth knowledge (for instance, by creating doubts about whether now's the right time to ask to close a deal with someone considering or evaluating).
I always sound like I know exactly what I'm talking about, and often I don't, so don't hesitate to tell me I'm wrong; I'll learn from it. My sense of it is that it's very hard for a tech person to be a good salesperson. Not impossible, but not statistically favored.
What I'd add to your list above is passion. The best sales team are those that really believe in what they are selling. Of course, great sales people can sell anything even when it's rubbish - but for that you need a superstar sales person. For mere mortals passion is key - and that often comes from those who knew the product inside out- ie SE.
What I haven't mentioned is those that made the SE transition to sales very much left SE behind. They could do their own demos but they don't. They need to transition to all the stuff you have above. But if you can retain the product passion - and the marketing/benefits/product knowledge background, you have a good advantage.
Ah, gosh. Now I need to retroactively reconsider all your posts that I took at face value. Well done :/
SE (or presales as many places call it) is a great job as you can move into almost any direction you want very easily. You are essentially the ultimate all rounder - you must have extensive product knowledge, great communications skills, good sales awareness, marketing skills, work with the development team and services too - so you can then go into any of these directions actually very easily. I worked in presales for about 6 years and personally moved into product management which I love. If I wanted to I could move into development but I don't had those skills - but if I found a developer with a presales background I would snap them up immediately - would be a killer skill set combo; or a perfect startup founder.
So yes, I completely agree that SE or presales is the perfect job to do to get exposure to nearly all functional areas of business. And that is ideal for 'founder training' or simply if you don't know where you want to end up so want to learn what each part of the business is like.