The answer to what to take into account is as much as you want. You can go all the way down to temperature gradients in the core to the interaction of individual microplates. You could make a thesis our speculative plate tectonics. The basics of plate tectonics could be explained in an hour but the details could take a lifetime. We can't really answer how far you want to go for you.
A few obvious issues with your map.
first congratulations on having one of the best tectonics maps I have seen in a while. Your continent shapes look real.
You have lots of oceanic plates and only one maybe two spreading centers, which somehow have an island chain on it. if you want that island chain it should be a subduction zone. plus you want at least 2-3 major spreading centers, probably a lot more.
Almost all your continents are complexly surrounded by subductions zones, this especially does not work with so few spreading centers. continents should have large sections of oceanic plate attached to at least one side or have a spreading center one one side. you may want to refresh your knowledge of how rift valleys turn into oceanic crust spreading centers. most of your oceans should have
you have mountains in the center of your "cloverleaf" continent, but all the continents are moving away from each other. Again you want to consider what rift valleys are. Not every mountain range needs a plate boundary. Many mountains on earth are from extinct plate boundaries, (Appalachians, alps)
you have oceanic plates moving towards each other with no island arcs, if your oceans are shallow enough for spreading centers to form island arcs those subductions zones should have massive island arcs. Every edge of every plate needs to be one of three things divergent, convergent, or rarely transform boundaries. you may want to draw them with a different color for each of these it helps you keep track.
your southern polar continent is completely surrounded by plate boundaries, if you look at earth most plate boundaries are in the ocean, plates are rarely just continental. They are usually oceanic or oceanic and continental together.
I offer up here a small fix, delete borders in neon green, (the doubled lines make editing a pain btw) but you still need to fix some of your continental plate boundaries, I suggest moving the ones marked in red off shore. Yellow arrows are obviously new motion directions. I have not considered magnitude of motions the arrow length is just for ease of seeing.
Earth map for comparison