1. They speak the blah and can have tusks. They are not actually descendant from Elves, that is just a folktale.
2. Goblins are smaller and less muscular than regular orcs, so they rely more on agility than strength. But that doesn't mean kung-fu. That usually just means the ability to dodge and run away. Their strength is their ability to just weasel out of situations, or use their ingenuity. They are also very durable as they are commonly used as toys by regular orcs. A goblin would make weapons in a similar manner to any other race. You would most likely have a workshop scaling to the size on what you're working on. Whether it be a siege workshop or a workbench. Generally Goblins will RP building like any other race (but in an orcish manner and technology for orcish culture) and then showcase this to the Warnation. Whether it be through an event or forum post.
3. Not I.
4. Generally goblins share the same culture orcs do. They like to "klomp" or help "klomp" but just usually do it in indirect ways. Gragarn also likes to carry Goblins and throw them around. They are basically just smaller, more intuitive, and more durable orcs.