Father's educational certificates issue

[vaib]

Hi
I'm sponsoring my parents' B2 visa.
While filling DS160, I'm facing an issue.(well, a bunch of them actually):
1. There is section related to firearms training. My father is a retired customs officer who carried gun. I'm going to check Yes in this section. Would this affect the visa process?
2. My dad did his Bachelor of Science from 3 different colleges for his 3 years of BSc. 1 year from a different university, last 2 years from the same university. Also, there were gaps in between. (Reason: He had no money, so was working to save money). Now, he only has the graduation certificate from the university from where he did his last 2 years. His first year documents were destroyed years ago. What do I do here? Should I just mention the last university name and the years? Please advise.
3. My dad is retired. He changed multiple jobs, ultimately settling onto his last job (13th job) and retired doing that. Do I need to mention all the 13 jobs? I don't think he remembers all the details like supervisor name etc. He started his 13th and his final job way back in 1980.
Would really appreciate the help.
Thanks.
Vaib

[immihelp]

1. You should mention it. It should not affect his visa.
2. Mention the details of the last college from where he graduated.
3. You really need to put only last 5 years of employment history.