I have read on the internet that the la-ea2 SLT adapter locks aperture at f/3.5 when using alpha lenses for AF. Is this correct and is this still the case?
1) what's the process for getting faster than f/3.5 on fast primes? Does it have to be all MF?
2) what happens if using a telephoto lens at f/5.6? Can the adapter even AF then? Or does it need f/3.5 to AF at all?
The answer to your question is: No.
La-ea2 technically transforms Nex to work like an SLT With full contr and pdaf as well. This includes AF of screw drive a-mount lenses as well.
Sony A55, Sony NEX-3, Sony F828