Contact form 7 editor problems

Hello, im quite the noob first of all, and have 4 questions.

I recently downloaded this addon since I did not like how my contact form looked.
My first problem is with the contact form rows, I have 2 columns of text-boxes, as you can see in the first screenshot, but the last textbox, witch is on its own under the 2 columns, is way to small, I would like to make it bigger, so that it covers the both columns.

My second problem is the gap between the “2 columns”, its a little to short, where can I edit this? in my editor, it looks like all the messages boxes have their own line, I will send a screenshot of this aswell.

I also wonder if I can have text as a placement holder, inside the boxes, if nothing is yet typed, like inside the box with a gray tint or something like that.

My final question is that my text inside the textboxes starts far in, not at the edge, this looks quite weird, I will send a screenshot of that aswell.

Big thanks for reading, and hopefully someone can help me with some of my problems!

Here are the 3 screenshots of my problems if you did not understand completely:
https://gyazo.com/b33756569e1e195a3844806c0d1f8b85
https://gyazo.com/c006bb97c8518680fc0c3c539d0c3845
https://gyazo.com/926647d79dd8f9e26121fe5198fddd7e

The page I need help with: [log in to see the link]