Re: Need to move the board more to the left.
I don’t know about image sizing, but there might be a plugin. Go to the Extend tab and do a search.
You should be able to move your layout around by changing the theme’s style.css file. I learned to create my theme by drastically changing one css setting at a time so it was obvious what the setting did, then getting it how I wanted. Learning what your theme’s stylesheet does is essential if you’re going to modify it in future.
Personally, I think there’s nothing wrong with white space on a forum. It can give a much cleaner look.