Welcome to the grand (and tougher than usually one would imagine) endeavor of world creation.

Your logic appears sound and all, but there's one big/huge detail you should address right away and that's your understanding of tectonics. The plates your figured are just as fine as any others, but the nature of the plate borders is either unclear or wrong. Here's what I suggest - start by choosing a few of those junctions to be bottom of the ocean rifts or newly formed continental rifts. Now, any plate adjoining those junctions will move AWAY from that line. The whole plate. The whole plate (save slight bends) moves in the same direction.

I can see a huge rift in your map: on the western side of the pink plate and then joining with another rift that runs on the south margin of the gray-blue plate. Maybe you could try this... Once you do this, the parts of the world where the plates collide to form mountains appear effortlessly.

Climate will come at a later stage. Be patient.

And good luck, enjoy it!