EEA Partner Visa Application

Hi,
I am a EEA citizen and I want to apply partner visa for my non-EEA partner who is in UK on a work visa currently. I have a few questions.

1. Does my partner has to give up his current work visa status in order to apply for the EEA Partner visa?
Or is he allowed to maintain his visa status concurrently so that he can apply for his ILR after staying in
UK on work visa status for 5 years?
2. How long does the Partner visa process take from Submission to the approval (BRP residence permit)?
3. Do we both need to send our passports for the entire duration of the application processing? Or the passports will be returned as soon as the application documents are reviewed within 2 weeks?

Please help clarify.
Thank you.

I'm not sure about "work visa", but your partner will need to submit their BRP as part of the application and if their application is successful, tier-2 BRP will not be returned. Instead they'll receive EEA FM BRP.
For timeline you can check relevant topic on this forum.
You don't need to submit your passport, instead you can send your ID. But your partner will have to submit their passport, though it can be requested back once you receive COA.