1) The Jamagirk is not really used by laity and even among the clergy it is not used as much. Would it be considered "odd" to be using it on a daily basis?
It isn't? I don't know about that. Not odd at all to use it for prayer, but maybe a little unusual to be attempting to pray every zhamerkutyoon every day. Just remember that everything in the Jamakirk is OK for lay prayer -except- the priests' prayers that include Khaghaghootiun Amenetzoon. Those must be omitted.
2) How many offices per day should I be doing, simply Aravodyan and Gisherayin Jam? I am off during the day for the most part so should I be saying 3rd 6th and 9th hour as well?
I appreciate your piety in wishing to do this, but remember that the Jamakirk was collated by monastics for a monastic prayer life. As a lay person, you are not expected to pray the entire thing every day. Nor could you by yourself. Aravodyan and Kisherayin are probably fine.
3) How do I use it correctly? I have the 1985 Jerusalem edition of the Jamagirk and sometimes when I follow along with the services at church, different hymns are sung which are not in the Jamagirk itself. Is it ok to "abbreviate" the "breivary"? (pun intended)
Praying the Jamakirk alone as a layperson means you are not able to do an entire canonical service. It's no more than a regimented series of prayers and songs you are practicing in your private devotion. Just keep that in mind. It's your personal prayer life. Do what fits your life and your schedule, and don't overwhelm yourself with the minutiae and formalities, because at the end of the day, it's your personal prayer.
Just my opinion.