The best settings and mods for this printer

I'm trying everything now to improve the quality, but I don't have the time to get some new rods, so I'll just keep using these. I'm now going to print the corner braces tanephar mentioned and hope that'll make a noticeable difference.

I also tried updating to a newer version of cura, because I was still using 15.04.6. Can anyone maybe share their settings for cura 3.0.4?

If the project in the end turns out to be a success, I would also like to share it with you guys