Rack vs Baking Pan vs Roasting Pan and Position
A higher-sided pan can end up holding more moisture in near the food, and prevent it from cooking up quite as quickly than in a sheet pan.  This won't be as noticeable in a convection oven.

If something calls for placing it directly on the rack, it likely won't crisp up if you put it in a pan for this reason, as well as reflecting (shiny) or absorbing (dark metal) the radiant heat before it gets to the food.  Glass dishes will let the radiant heat through, so the bottom will brown a bit better, but there's still the moisture issue.

If by 'roasting pan' you mean a rack suspended above a pan, then it'll be a little between the two -- you won't have the food necessarily steam underneath as much, but you still have a pan there to deflect radiant heat.

As for location in the oven, it'll often affect how quickly the top of the food cooks vs. the bottom.  (closer to the top element means the top will cook more quickly)