[Theme: FlexForm] SideBar Positioning/Changing Post-Width/Changing Searchbox

I know some CSS/HTML, not PHP yet so much. I would like to make some customizations. I don’t expect you too design my site! I’m still learning, & some answers I can’t find online. So Please bare with me, & thank you in advance for any pointers in the right direction(s).

CURRENT FLEXFORM SITE: https://69.195.124.214/~maturesi/

1. Moving My Left SideBar, ALL THE WAY TO THE LEFT.
So in style.css I changed the padding below from 20px to 0px.

}
.sidebar.left-sidebar {
    padding-right: 0px;

Nothing happens. I’m assuming there is a another line of code I’m missing? I’d like the sidebar ALL the way to the left.

2. EXPANDING THE WIDTH OF POSTS/PAGE CONTENT
I’d like to expand the width of both the pages & the posts on my site to 820px. How would I go about making these changes in my stylesheet?

3. KEEPING THE SEARCHBAR IN THE MINI-HEADER ON SCROLLDOWN
When you scroll down the header turns into a mini-header. But the search bar disappears. Is it possible to keep it in the mini-header as it scrolls down?

4. SWITCHING OUT THE SEARCHBOX/STYLE
I have my own custom searchbox I designed on a Blogger. I’d like to replace the current “animated” searchbox with my own. How would I do this?

Lastly, if I had money I’d pay someone to help (and I would promise too) when it comes in. But any help with any of these things, in the meantime would be invaluable and appreciated.

Thanks for any help guys!

Best
J