Really, it is a very good idea to join up into a established alliance, they offer aid, tips, and protection required to really get on your feet in this game- but I wish you the best of luck
I think of it like a rts when one soldier= a battalion to keep things simple and less complicated- the same mentality is put towards the improvements in cybernations
Navies are useful for two main reasons: blockades and support of other attacks. If you are not often attacking countries with more 1k land or and are not anticipating war with such nations, than it is not time to consider the immense cost and upkeep of a Navy. The reason they are worth maintaining is due to their large upfront cost and build per limit each day involved. Another good point worth mentioning are carriers add extra aircraft to your nation- but it is only worth investing in at higher levels of nations. Save the cash and spend it on tech and save the rest for a warchest.