No worries, a few comments on this stuff so far:
You can unlock the Editor limit (62 FPS is a weird limit mind…) by using the console command (tilde key to open):
t.maxFPS 120
I use a 980 so I often set it to something insane like 250, and it still caps out 
I’m not sure if this is relevant to you or not, but SLI currently yields no benefit to the Editor.
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Second, the engine does tend to run quite hot on older cards. It has improved massively over time and will only continue to get better. I upgraded from a 560Ti not so long ago, and the heat difference in my room was certainly noticeable :P. It’s worth noting that all the additional draw calls and overhead for the editor do add a lot of processing to the card, you’ll get a surprisingly big frame-rate increase in a packaged build of your game, both GPU and CPU performance improve greatly. Closing editor panels that you’re not using can help performance too.
Hope this helps! It’s worth bearing in mind that the min recommended specs are considerably higher than the 580, (though I always found the 500 series held their power really well). All those supa-graphics don’t come free