You have already spent some quality time with GSTG to get to this point. We hope the following provides answers to your specific questions and gets you to the next step in your TG creation.
First, we strongly recommend the use of 2-cell key abbreviations rather than full-labels. The consideration of full-labels or 2-cell or 3-cell key abbreviations largely hinges on whether full-labels will result in the graphic becoming crowded (GSTG 3.1.4, 7.3.6). The use of alphabetic keys helps to keep the TG as open as possible, and protects your desire to maintain sufficient open space surrounding each tactile feature (as defined in GSTG 126.96.36.199).
If the TG map is still too cluttered, we suggest putting it on two facing pages. Follow GSTG 188.8.131.52 for placement and labeling of the key.
Second, there is no preferred set or specific order of use for symbols to identify points on the TG, but the list you have provided (which appears in the entry for "point symbol" in Appendix I on page I-9) could be used. So your first symbol could be a dot or circle, the next a square, then a triangle, and so on. You can use hollow symbols and then filled/shaded symbols to expand the set of symbols available.
Third, as you have noted and as shown in the figure on GSTG page 3-37, print letters can also be used so long as they are tactually distinctive. However, following GSTG 10.2.7, letters that are tactually similar to the shapes mentioned above, or to other symbols used, should be avoided (for example, A, V, O/D/G, B/E, T/Y, etc.). This may be more of a concern for younger readers who are still developing their tactile discrimination skills, than for more advanced students.
Related to this, we will suggest just using the capital print "Y" rather than enclosing the "Y" in a box. Putting the "Y" in a box puts lines very close together such that it may be misinterpreted as a texture rather than a point object by some readers.
Also, braille symbols should not be used as key/point symbols. The risks in using braille (including the full cell) as a key/point symbol are that it can be interpreted as the braille symbol(s) itself, or as a texture.
Whatever symbols are used, it will be relevant to make use of the tactile graphic proofreading procedures to ensure they are clear to the readers who will use the TG (GSTG 10.2, especially 10.2.23, 10.2.24).
Fourth, GSTG 5.8.1 provides definitive advice on how to create the key items, and what letters/braille symbols can be used in the key and map. In particular, one of the braille symbols in key entries must contain lower dots (GSTG 184.108.40.206) so that when placed on the TG itself the key entry is not mistaken for a texture.
Fifth, GSTG 5.7.1 indicates that there is a specific order in which a key should be presented:
- Area textures
- Line textures
- Point symbols
- Alphabetic key
- Numeric key
Sixth, we will recommend that you move the compass rose out of the body of the map. As indicated in GSTG 220.127.116.11, the compass rose should always be placed at the top left of the page.
Finally, in your draft tactile map, the "N" indicating "North" on the compass rose is shown as lowercase. It should be brailled as a capital "N". Following GSTG 18.104.22.168, it is not necessary to add the grade 1 indicator even though only the capitals letter "N" is used.
Please let us know if this addresses all of your questions!