I think so, however the common areas, including exterior, would need to be Lead Free as well.

I believe that to be the most common practice at least in my market.

The answer will depend on how you and your partner acquired the property.Did you acquire the property as tenants in common or through an entity?

The most common pattern I see is landlords just... holding.

Really common when we're doing projects like that.

.- The wasp nest that you noticed underneath the front porch and decided to disregard.- A hot tub that isn't wired correctly because you hired the housekeeper's husband to do it for you for 50 bucks.- The shiny new barbeque grill that you had the housekeepers place on the wood deck next to the railings.- That quirky, and warm, light switch that you didn't notice because you haven't been to the property in a year.- The shower that you noticed is awfully hot but failed to check into it more before you left.And so on. 

If we notice something that isn't in the lease that we feel is important, can we add an addendum or if we agree to "as is" is that also the lease or just the property?

By the way, these are the choices I have:(OAPR) PROBATE/GUARDIANSHIP ORDER APPOINTING PR/GDN(OAW) PROBATE ORDER ADMITTING WILL(ODPR) PROBATE/GUARDIANSHIP ORDER DISCH PR/GDN(PBO) PROBATE/GUARDIANSHIP MISC ORDER(PTPR) PROBATE/GUARDIANSHIP PETITION DISCH PR/GDNThese are some "trust" categories:(TRNOT) NOTICE OF APPLICATION(TR) TRUST

A duplex or ADU could work, I was interested in single family houses because in some locations Duplex's/ADUs are less common and SFH typically cost less.  

OWNER will attempt torepair the problem as soon as possible upon notice by the TENANT.