didn't read through the posts but i think it is within normal limits for a child who was exposed to spanish as an infant. we did sign language with our son starting at 8 months and by the time he was 18 months he had about 50 signs (and only 8-10 words, not stringing them together yet.)
at 23 months he won't shut up. talks constantly has many many words, and said his first 4 words sentence a few weeks ago "mommy, daddy, stop talking!"
it's fine to get your child assessed but make sure that they evaluate in context of the situation.