A couple of questions regarding pro forma analysis

[Cam Forrey]

Hi guys, longtime bigger pockets lurker here.

I am looking to buy a 3-4 unit property in my hometown to buy and hold. A couple questions for everyone on building good pro forma analysis before I get in touch with a seller.

1) How do you determine a vacancy factor for a 3-4 unit property?
2) How much should I put in the cash flow analysis for repairs/maintenance?
3) I plan on living in one of the units, from a tax perspective is PMI a deductible expense?
4) In my analysis I have a vacancy loss, management fees, replacement reserves (repairs and maintenance), property taxes, insurance, PMI, and utilities. Any other expenses I need to be including in my analysis?

Thanks for any insight, looking forward to being a part of the community.