These are honestly pretty simple once you draw out the steps, and they become easier to figure out intuitively the more you practice the 4 steps.

Here's how I have my notes for 3.1:

A railroad will not be successful unless it serves its customers well.

1. unless

2. not success, serves

3. /not success > serves

/serves > not success

success > serves

/serves > /success

4. if a railroad is successful, then it serves its customers well

if a railroad does not serve its customers well, then it will not be successful

If a clause already has a negation, I will write it out with the "/" and THEN get rid of the double negatives where applicable. The opposite strategy was used for the 2.x examples

Si!!!! Familia de Valencia y ahora viviendo en NY, y tu?

I'd love to be added as well! Currently aiming for 170 in August

for 7, isn't "whose" also a referential for "an organization"? Thanks!