Great Thoughts overall.
I will only add a different perspective On 485J. Using company lawyers has its pros and cons;
Pros;
1. Lawyers have seen many cases so they can decide what will and will not work.
2. Saves one the headache of poring over 485 JD Vs current JD
3. With the changes in SOC code it is always a challenge to pick the right SOC for minimal risk of rejection.
Cons:
1. If one had transitions in their career the individual is best equipped to connect the dots between the prior JD and Current JD
2. Depending on the relationship with HR and Manager one can emphasize duties that are similar in the 485 JD to the new JD
3. One has the latitude to pick a SOC code that is in the right zip code rather than be at the mercy of lawyers
4. Lawyers will generally take the conservative approach when the need may be for pragmatism.
In summary If you have a situation that needs explaining for 485J you may be better served by doing some homework on your own or by engaging your own lawyer. Company lawyers are paid by the company so they will do everything for their client first, next for you and last for USCIS.