1. You have 2 options. Either go to
Frontier Options -> Misc and select Disable Editor Style or download an updated theme here.
2. “related posts”? The theme doesn’t have any “related post” functionality. You could ask the author of the plugin you’re using. If the issue is just css related then a screenshot won’t really be of much help. You’ll have to post a url that shows the problem so that I can inspect it.