I've totally broken #1 at D3 and made the S16
Example: season 79
Grinnell in Crum. Average athleticism was 41, average defense was 47. I only had one guy with an athleticism >50, and that was a 51. Made the S16, albeit as a 12 seed pulling off a pair of upsets. You can do it with lots of shooting
The next season I'm pretty sure was below on both athleticism and defense as well and made the S16 as a 4 seed.
Those, however, were both under 2.0 when player ratings were lower at D3. It might be up to 50 now - i haven't tested that theory
For #2 - i find it greatly varies by scheme. At D3, in a flex offense, I find it tough to have guys with LP <90 become go-to scorers. In a motion offense, I find they can have much lower LP ratings and succeed