I just sawn there is another two symbols in spanish keyboards, but they are not as important: "º" and "ª", wich are the equivalent to english "st"(first) for masculine and feminine respectively (and for second, third, fourth... in spanish the symbol are always these). And Catalonians use "ç" and "Ç", that's another letter for an smaller group, but could be great to have (altought I am not catalonian and don't use that symbol).

So well, there are 8 symbols to add if possible. Or 7 for complete spanish. Or 5 would be enought.