Low mileage/infrequently driven vehicle maintenance
 

I have a 13 gt premium that gets driven only for pleasure. Typically about 2 or 3k a year. Currently it has 16k miles on it. It gets 'stored' (garage) during winter months and during ice hammers from the sky months (hail). Typically 2 to 3 months at a time with no driving. I use a battery tender and try to at least start it up every couple weeks during those periods. I leave it with <1/4 a tank of gas and when I start actively driving it again I first fill it up to get fresh gas into it.

I put pennzoil ultra platinum full synthetic in it and it gets changed mid summer once a year.

I have two questions:
* should I do more when it's 'stored' (fuel stabilizer, up on blocks, drained tank, etc.). Am I damaging the engine leaving it for weeks at a time without oil circulation. Other concerns?

* what things do I need to do different maintenance on even with low miles (fluids, etc.). It has stock ties are only about 1/3 of their tread life and have no visible deteriorarion, but are 6 years old.

And in case its a question, I love the car and intend to keep it till I die so I try to ration my use but want to make sure I am doing the right things to keep it going that long.