title_body: How would I make an efficient, written, language while still providing the least ambiguity that is reasonable?
upvoted_answer: First a in this form brand new fact from natural languages: All natural languages are of approximately the same efficiency despite their quite noticeable differences (some languages are spoken at a rather fast pace in syllables per second, but than the information content of a syllable is lower than in other languages that are spoken more slowly). The reference is Christophe Coupé, Yoon Oh, Dan Dediu, and François Pellegrino, Different languages, similar encoding efficiency: Comparable information rates across the human communicative niche and they give a value of 39 ± 5 bit/s.
  
  So you can expect that a naturalistic constructed language will fall in about the same range; maybe somewhat less efficient, because it is difficult to get things just right by construction that have been optimised by language evolution over a long time.
  
  For completely symbolic languages, look up the term pasigraphy and take a glimpse on some systems that have already been invented.