Basic question, can you speed fly with a paraglider?

Thank you!

Using a larger airfoil / paraglider for speed-flying is possible and people do, but it is often called Para-Skiing.

Safer, both yes and no - yes you have the extra lift and higher glide ratios with the bigger gliders, but also not safer as you would be travelling slower and with tight turns could cause wing tip collapse as the glider doesn't react quick enough. The idea of proper Speed-Flying is fast, low level flights with a small glider.

At what point does Speed-Flying become Paragliding - from manufacturing data the cross over reference point is around 20m² - Bigger than 20m² is Paraglider. Sub 20m² gliders are normally used for Speed-Flying or Hike and Fly when you are just looking for descent.