The only difference between starlanes and star-to-star is that with starlanes, some of the connections are the "express" meaning faster to travel, and is visible, while other connections are "off-road" or slow, and invisible lines. With star-to-star, all lanes have equal travel cost (multiplied by distance), and are invisible.
Another additional benefit of this system is that I can add a flag to each object in the galaxy "BlockPath", which if set to true, will remove any starlanes that intersect with this object. So for example, you can't travel through a black hole like in MoO 2.
Stargates will be a special value stored in the starlane class. Each starlane class can hold a list of empire's modifications. So if you have two systems with stargates, you can use them to travel in one turn, while other empires can't use your stargate. Or you could even slow down your enemies by increasing the travel cost of starlanes connecting to the affected system.
While the ships still use the grid-based system, I've started work on starlanes and visible drawing of them (will be improved in the future). Here's a preview:
The goal is to support both starlanes and star-to-star, you select which one you want through game configuration.