UKM Referees and Other Questions

Hello - I'm looking for help with my UKM form.
Does anyone have experience, positive or negative, with their references? I don't happen to know any cops, ministers, teachers, etc. I was going to use my friend who is a senior HR person, and a former boss who owns her own business. They will both be US references as I'm not living in the UK yet.

Also, my only potential "criminal record" is 3 speeding tickets, the most recent was over 20 years ago. They were in other states and I'm not even sure there is a record at all. Is it best to just estimate when and where they were, which is really all I can do?

Will the HO be keeping my US passport for 6 months? If I need to leave the US in the meantime, would I get a temporary passport from the State Dept?

And please forgive me if I'm asking questions that are answered elsewhere - I was very happy to find this site and I'm just excited to connect with others who've been through this.
Thanks in advance

Here is the full list of accepted professional referees:

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/421217/Chapter_6_A_Referees_-_list_of_acceptable_professional_persons.pdf

While I'm not hugely familiar with the UKM application as not too many people qualify, this is a good thread on one done last year (when they were unable to do biometrics in the US, that has been fixed now).  This person DID get a second passport.

http://talk.uk-yankee.com/index.php?topic=87560.15