Lots of ways to agree there.Long term leases can be assumable, "subject to owner's approval, such approval not being unreasonably denied" is standard language.

Some may be unreasonable and not required, but if the previous owner did nothing for 20 years you probably have some issues that do need to be addressed.

Is a prepayment penalty of one year unreasonable.

RSO properties will allow for eviction if a tenant is "at-fault" according to this list:https://hcidla.lacity.org/Eviction-Tenant-is-At-Fault-Owners#3 states, "Unreasonable interference with the comfort, safety or enjoyment of other tenants, or damaging the rental unit or the property."

Although the seller is willing to offer a credit, I felt that was an unreasonable timeframe so this was helpful to hear. 

Large downs are unreasonable.

After their demand, I pointed out to the tenant that it was unreasonable of them to leave valuables under the area they knew needed repairs and expecting compensation.

IMO, that's a completely unreasonable analysis of the situation.

You are dealing with an unreasonable tenant.

Not sure about california laws other than they are incredibly unreasonable for landlords.