Can I cook with fresh cauliflower, even if the florets have developed some browning, if I cut it off?
Yes...it's just some oxidation unless the cauliflower is limp and mushy.
You might want to soak it in some white vinegar and ice water to refresh it if it's past it's prime.
One application for cauliflower I've been using is cauliflower couscous. You use trimmed florets..and processes in a mini-prep in small batches to make a 'couscous' type texture.
Lightly saute with olive oil a bit of stock and salt--lightly you don't want mush you want crunch.
Use as you would couscous for a base for Moroccan stew. Or topped with simple veggies with lemon juice with Middle Eastern/Mediterranean type seasonings.
yes, remove the brown part & use as usual unless its mushy or smells.
For a quick snack, I grate the cauliflower on slices of bread, top with shredded pepper jack & toast till golden & crisp, comfort food when eaten with Ketchup!
Just brush the brown spots with the back of a knife and it will be fine to use!
A cauliflower will have a less delicate and more cabbage-y taste once the little brown spots appear. But they won't hurt you. ;o)