I dimension or constrain everything. Geometric constraints are (should be) obvious and take the place of many (most) dimensions.
The dimensions are the dimensions that will be needed out on the shop floor. By fully constraining everything you ensure that the model is not accidently released for manufacture with a missing dimension. (I worked out on the shop floor for 8 years - I can tell you that missing dimensions is a costly problem.)
Really hope I can build this....
Did you verify the specs on the threads.
As indicated earlier 7mm is an unusual thread.
Measure the diameter of the thread.
Typically it will be slightly undersize. A 7mm thread might measure something like 6.8mm.
Find the pitch by measuring the distance across the crest of 11 threads and divide by 10 (you can just measure the distance from one to the next, but it is sometimes easier to get 10 distances and move the decimal place)
The diameter and pitch should match the list in the aviable Hole Feature.
Yes, use calipers. (there is a special tool to find pitch, but you can do this with calipers as described.).
You could also go to the local hardware store and purchase several nuts of sizes close to what you think you measure. (Be sure to keep them labeled.
You measure the external thread diameter (rod) not the hole.