¡Hola, Sergio! I can't read your entire question, but I assume you are looking for examples of when one would use a gerund following the preoposition "to" other than in the phrase "I'm looking forward to ...". Well, I don't believe gerunds follow the word "to" that often, but it is commonly used in the sentence structure "everything from ... to ..." . For example, "I love sports -- everything from skiing to swimming." or "One needs many skills to be a good hockey player, everything from skating, to passing to shooting." I have used sports examples, but you could use these structures with any topic. Perhaps there are other uses of "to + gerund", but I can't think of any right now. Hope this helps.