What are my rights if my landlord is not maintaining the property?

Your rights are limited, and you may not have effective recourse. If you feel that the landlord is violating the lease by not providing you what you are paying for, you could sue him if need be for breach of contract (since a lease is a contract) to recover compensation. The problem is that if the lease does not specify some of these items, it may be difficult to establish in court that the landlord has in fact breached the lease. For example: a $75/month pet charge is usually to cover the landlord against the potential cost of the mess and damage pets do--unless the lease actully states that the yard is fully fenced or pet friendly, you most likely cannot claim any violation because you are paying this money but the yard was not fully fenced, since the payment was not necessarily for this.

Similarly, you could possibly look to bring a fraud claim if the landlord did mispresent what you were getting or paying for, but it requires a specific misrepresentation. So, for example, if the landlord said you were getting a (working) garage but you didn't, you may well have a claim--but if he never indicated there was a garage (though if he told  you there was a garage, the assumption, unless he specifically stated otherwise, is that it's functional), you would not have a claim. However, even if you have a claim in this regard, it may not be worthwhile bringing a legal action, since the amount of money you could recover is essentially the difference in value between the home with a working garage door and one without, which might not justify the cost and time of litigation.

Finally, while rental properties are covered by what's called the implied warranty of habitability, or the obligation to provide habitable premises, none of the conditions you describe are bad enough to constitute a violation of this warranty, since the home, as you describe it, is habitable.