As booz mentioned length of leases, maintenance and improvements...

As booz mentioned length of leases, maintenance and improvements are all negotiable.

For me my preference is a minimum of a 6 month lease, but ultimately a 12 month lease is preferred. Probably if this is your first lease on the property it is best to keep it to 6 or 12 months as it allows you to scope out how the property is managed i.e. maintenance etc, and it also allows the owner to get rid of a bad tenant (one that has repeatedly not done the right thing during their lease period). After the initial lease if everyone is happy with one another then a longer lease period could be negotiated - bearing in mind that the owner may want to include some rent reviews within that period otherwise is may not be in their interest to sign a longer lease. Alternatively you could go onto a periodic lease as that allows rent reviews within certain time frames - however neither you or the landlord will have any stability out of this arrangement as either of you could give notice to the other for termination of the lease. After the 12 month period I tend to either re-sign another fixed period lease with my tenants or if they want to I let it lapse to a periodic lease as I have already had a reasonably good period out of them if they decide to leave and I have to find another tenant.

As for making improvements well that is a bit of a tricky one. The reality is I don't want my tenants doing anything directly to my properties generally as the standard or workmanship by many people can be low. If I do the improvement or maintenance and something goes wrong that is MY problem, however if you do an improvement or some maintenance and your damage something then you may be liable for the damage.

I am sure you have the best of intentions and many of your improvements could potentially be in the interest of the owner but be careful. Depending on the owner/agent you spending money on the property may not be any guarantee of keeping it. Many owners will do a level of improvement to keep good tenants and improve the property, but remember owners are not rich as many think - it just depends on their cash flow and other liabilities at the time.

Personally I have just had ducted evaporative air-conditioning installed in a couple of my rentals, and always take into consideration tenants requests - but there is no guarantee anything will be done or that it will be done in the time frame the tenant would like it to be done. General maintenance is always done asap by me or if necessary a 3rd party contractor (i.e. electrician etc) - basic things such as changing a tap washer are my responsibility but things like changing a light globe are your responsibility.

Things like gardens are probably the best thing you can do to improve a property - it make the place look allot better and you aren't potentially damaging any of the existing improvements.