Where are the recommended jacking points? Also, if I want to take the front subframe off is it safe to hold the car by a scaffolding pole/strong length of timber etc placed right across the front of the car and supported on axle stands ie the floor taking the weight?

I could'nt say about a Rossa but on the 2 fibreglass monocoque Mini based cars i've had dealings with i've supported them with a piece of 4"x2" between axle stands at the bottom of the A or B post, ie:- where the inner and outer sills and the post all all meet with no ill effects. Jack under the subframe carefully as you would with a Mini.

Many thanks