I don't think so.As far as I know, madd-e-munfasil should be prolonged by 2/2.5/4 alif in length (same for madd-e-muttasil). Each alif being equivalent to 2 harakat in length. Only madd-e-laazim and madd-e-leen-laazim are prolonged to 3/4/5 alif length.
So short answer is "yes"; madd-e-munfasil can be prolonged to 2 counts (but no shorter).
I don't think so.
I think these are the lengths:
Muttasil - 4/5 counts - 6 if you're stopping on it
Munfasil - 4/5 counts but can be 2 counts (i.e. read as madd tabeeyi)
Laazim - 6 counts
Leen - 2/4/6 counts
One alif is two counts as far as I know.What exactly do you mean by count? One alif length or half alif (i.e. 1 harkat)?
I am simply quoting from Dawat-e-Islami's Madni Qaida (see attached)