Regarding BeoLab 3s, toe-in is a good question.
In theory, yes, toe them in. In practice, it doesn't seem to matter a lot, particularly when you use them as I do, close to the listener. In the studio, I have them on each side of the meter bridge of my console, a little more than 1 meter away from me, with NO toe-in (mainly for appearance reasons – remember, also, that I may have a client sitting next to me and whatever toe-in I have isn't going to work for the client). On location, I set them up on whatever table is available and toe them in.
If you have them away from you (say more than 2 meters in a typical room, I guess I'd toe them in (and that's what I do in my living room, with the home theatre install with an Avant).
I hope this answer helps.
Best regards,
Dave Moulton, Sausalito Audio LLC