EB3 to EB2 porting - seeking advice due to change in nature of job and adding spouse

[eb3toeb2user]

Background: I have Bachelors in Arch and 5+ yrs of experience in 2-3 architecture firms. But I decided to change career, did a Bachelors in Nursing and I am now a nurse for last 1 yr. I don't have any IT experience. I filed an EB3 as "autocad designer" when I was into architecture and got my EAD (PD: 2005) but without my spouse who was in India then.

Objective: I wish to port my PD to a new EB2 so that my spouse will also file & immediately get GC. My spouse just came back to US and is looking for a job on a recently approved H1.

Questions:

- How is 5 yrs experience proven in EB2? Can my nursing employer combine 1 yr nursing as "similar job" with 5 yrs architecture experience? Or can an IT firm consider my 5 yr architecture "autocad software" work as IT job experience to file an EB2?

- My previous architecture employer, who I left in 2007, can sponsor EB2 in good faith for a senior architecture job provided I can take care of all costs. I can engage an attorney but is it advisable that a small firm (maybe a sole proprietor) file an EB2?

- Is there a chance that my spouse can file EB3 and still get EAD even though my PD is 2005? I have heard USCIS sometimes does this by oversight.