well i have played FFIV upwards.
to be honest, from VII upwards are the best, apart from IX, which became to much of a cartoon..
Personally I think there are more people who loved FFVI more than FFVII.
i don't think so, look at Square's release statistics. FFVII made nearly $3.2 million, FFVIII made around $2.9million, i don't think FFVI made that much. I personally think that only fans would have FFVI and below.