Love your work! I'll give these a go, although my understanding is somewhat rudimentary

TEST - see what you've learned
(2.8 - what part of the question)
1. 4/.3/2/.9/2s.=?
2. 50s.=?
3. 0/.22/5/.6/0=?
1. 4/.3/2/.9/2s. = {4/.3/2/.9/2, 0/.4/3/.2/9/.2}
2. 50s. = 0/.50/0 = {0/.5/0, 5}
3. 0/.22/5/.6/0 is unchanged due to no s?
(2.10)
1. 5+[3]7=?
2. 6s.+[.2]1/.4/5/.3/0=?
3. 4/.5/3s.+[6]6/.2/3s.=?
1. 5+[3]7 = 10
2. Got a bit lost, is this using info from 2.11?
3. Got a bit lost, is this using info from 2.11?
Got a bit lost with the whole of the 2.11 and 2.12 exercises, but I'm sure it wasn't your magnificent teaching style to blame.
I'm still absorbing your new and exciting concepts, so I can't answer the later questions

Thanks for this amazing insight!

Also, you haven't shown us 2.13 yet

So we can't have a go at:
(2.13)
1.6-[3]8/.2/3s.=? ( - in square )
2.5/.2/3s.-[.2]6/.8/2/.4/2s.=?
3.3/.10/10/3-[.10]5/.6/3=?