add other ingedients until everything is in proper proportion or start over
you put a lot of sugar in it ! He He
It depends on what the recipe is
If it has been mixed into the recipe there isn't much you can do. If it hasn't try soaking up the excess with a piece of bread.
your cake will look and taste like goo in the oven
Adding too much liquid, be it wine, water.
no
No, it will add too much liquid to the recipe and not enough sweetness.
This depends on the recipe and how much less you put in. If its a tricky recipe using yeast like croissants or just yeast dough then the yeast molecules may not have enough starch and the dough may not rise as much. If its in anything else and its not a huge amount (less than a quarter of a cup) then just use less liquid. Keep the solid to liquid ratio equal. If its more than a quarter of a cup just make half a recipe.
Wouldn't recommend it. It'll add too much moisture to the recipe.
Horseradish is a condiment that can be used with any recipes you like. It can be used in a sandwich or mixed with hummas for a spicy dip. Its also nice with roast beef too.
If you have put too much mustard in your fish, you can dilute the mustard by adding other ingredients. Fish cakes would be my choice (mix the fish with mashed potato, onion, a little flour, make into cakes and bake) or fish stew (stews are very flexible, add any vegetables you like).
I wouldn't put too much thought into that.