A family of Microsoft word processing software products for creating web, email, and print documents.
There are two ways to get the arrow to combine with the preceding character: Press the space bar twice after typing \vec, or type the whole equation (leaving the arrows to the right of the characters) and then click the down arrow on the right end of the equation box and choose Professional.
To get an arrow to cover two or more characters, put parentheses around the characters (they'll be removed by the Professional format).
I'm not sure what you mean by "the vector notation that looks like a fraction without the dividing line" but it sounds like a 2x1 matrix. If that's it, you can type the Linear format as \matrix(x\vec@y\vec) and convert to Professional. The black square below is what you get when you type \matrix and then type the left parenthesis. Typing the @ moves the arrow over the x, and typing the right parenthesis moves the arrow over the y; then converting to Professional builds up the matrix.
If you want more vertical separation, right-click the matrix, click Matrix Spacing, and increase the spacing between baselines.