Fine-tuning magazine layout for posts

Hello! I am new to the Parabola theme and enjoying it– thank you! My questions is regarding the magazine layout for blog posts:

1. Right now, in two columns, the posts clear both right and left. Yet, my post excerpts are of uneven length… is there any way I can fix this with some custom CSS so there would not be so much white space?

2. Has anyone successfully turned off magazine layout on other post pages? I have set up a second post page in addition to the presentation page + have a couple category pages and would like the option of having a single column there : ) Am not afraid of creating a custom layout if I need to, but do not have the PHP skills yet to figure this out on my own!

Thanks for any suggestions and help!