Tenant leave bbq grills, furniture, and trash in common areas and it is creating a fire hazard. Is this considered abandoned and I can simply throw it away? Also how would I enforce a policy on balconies being used as storage space? Are these violations reasons for eviction?
As a practical matter, you could start with a friendly reminder about courtesy to the other tenants.
If that does not work, you should send the tenant a 3 day notice to quit or cure , which specifically identifies the problems and the lease provisions violated.
Real Estate Attorney
You would need to read the lease. If these items are not addressed, you should hire a local landlord tenant lawyer to help you write an addendum or revise your lease.
What does your lease say about these things? As Mr. Kane mentioned, you can remind the tenants in a friendly manner, but if the behavior does not change, you may have to take further steps.